4.17am local time (5.17am UAE time): The 7.8-magnitude earthquake strikes near the city of Gaziantep in southern Turkey, but strong tremors are felt in Syria, Lebanon, Cyprus and Iraq and provinces around Kahramanmaras, where the earthquake occurs, suffer severe damage. In Syria, there are reports of poorly constructed or conflict-damaged buildings collapsing. Initial reports from Gaziantep say 70 people have died.
4.28am local time: First aftershocks felt with a 6.7-magnitude quake.
8am: The scale of the disaster emerges as the governor of nearby Malatya province says at least 140 buildings have collapsed. The US says it is deeply concerned by reports of the quake. President Biden directs USAid “and other federal government partners to assess US response options to help those most affected”.
9am: President Recep Tayyip Erdogan says an emergency meeting has been held with governors of southern provinces. Estimated fatalities rise to more than 200 and a growing number of countries announce they are sending support, including Azerbaijan which says more than 300 emergency personnel are being prepared to assist.
9.15am: In Damascus, President Bashar Al Assad held an emergency cabinet meeting to review the damage and discuss the next steps, his office said.
10am: People in Hatay province, Turkey, call for more emergency assistance on social media, saying rescue teams are overwhelmed by the scale of the disaster. The port city of Iskenderun is particularly badly affected. Critical infrastructure and historical sites suffer severe damage, including the runway at Hatay airport and a gas pipeline, also in Hatay province, and the 2,200 year old Gaziantep Castle, which is almost entirely destroyed.
11am: Reports emerge about the scale of the disaster in conflict-hit Syria. More than 300 people have been killed in northern Syria in government-held areas of Hama and Latakia, according to Syrian state media, while at least 150 have died in militant-held Idlib governorate, according to opposition-linked emergency services the White Helmets. Idlib is home to about one million civilians displaced by a decade of conflict.
Midday: Turkey says that about 2,000 emergency personnel have been mobilised and sent to Kahramanmaras, reinforced by national police. A major aid effort is under way to help those without shelter in freezing winter conditions. Meanwhile, Syria deploys the army to help affected areas under government control, including Latakia and Hama. The death toll in both countries passes 500.
1pm: China’s Foreign Ministry sends condolences to the victims of the earthquake. EU High Representative Josep Borrell and the EU Commissioner for Crisis Management Janez Lenarcic say teams have been mobilised from Bulgaria, Croatia, the Czech Republic, France, Greece, Hungary, Malta, the Netherlands, Poland and Romania to support the first responders on the ground. Italy, Spain, and Slovakia have offered their rescue teams to Turkey as well.
3pm: The death toll in Turkey and Syria surpasses 1,000 and continues to rise through Monday, reaching over 2,300 by 6pm Ankara time. Aid offers continue to come in, with Lebanon saying emergency service personnel will be sent to Turkey.
4pm: President Sheikh Mohamed announces a field hospital will be sent to Turkey along with rescue teams to both Turkey and Syria.
5pm: Authorities say they recorded over 120 aftershocks from the initial quake.
6pm: US Secretary of State Antony Blinken says the US is already mobilising disaster assistance.
6pm: Turkey sends 16 planes and 2,647 personnel from Istanbul to quake-hit areas. The UAE sends its first aid plane to Turkey carrying search and rescue teams and medical equipment.
8pm: President Sheikh Mohamed orders the dispatch of Dh50 million in urgent humanitarian aid to Syria. Turkey announces seven days of mourning. The death toll surpasses 4,000 in both Syria and Turkey.
Midnight: The Syrian Red Crescent says it transported more than 200 people to hospitals as it distributes thousands of blankets and mattresses.
1am: Syria's volunteer civil defence organisation, White Helmets, report more than 2,800 deaths and hundreds of injuries and families trapped under the rubble in north-western Syria.
2am: The Turkish Red Crescent continues to distribute assistance, including hot meals and blankets as night temperatures drop.
8am: More aftershocks reported, including a 5.6 magnitude quake. Two humanitarian relief planes from Iraq arrive in Damascus carrying 70 tonnes of foodstuff, medical supplies and blankets.
11am: The World Health Organisation warns fatalities could reach 20,000.
1pm: Turkey’s Vice President Fuat Oktay says the death toll has hit 3,419 while Syrian authorities say 1,602 people have died, pushing fatalities past the grim milestone of 5,000.
2pm: A 21-strong team of Greek rescuers arrives in Turkey, a development seen as historic by some who point to the strained relations between the two countries. Greece was one of the first countries to offer support to Ankara following the earthquake. Meanwhile, the UK says its rescue teams are delayed but will soon be en route to Turkey.
3pm: Unesco announce they are preparing to send assistance to two World Heritage sites, the Old City in Aleppo, which had been partially restored before the earthquake struck, after suffering damage during the country's civil war, and a historic fortress in Diyarbakir, Turkey.
4pm: Mr Erdogan on Tuesday declared a state of emergency in 10 provinces devastated by the earthquake and imposed it for three months, permitting his cabinet to bypass parliament in enacting new laws and to limit or suspend rights and freedom.
7pm: Aid flows from Turkey to north-western Syria were temporarily stopped due to the fallout of the quake, a UN representative said, leaving aid workers grappling with the problem of how to help people in a country fractured by civil war. The cross-border aid operation overseen by the UN since 2014 has been crucial to Syrians who fled Al Assad's rule during the conflict.
8pm: Egypt said the country's President Abdel Fattah El Sisi had spoken to Mr Erdogan in a phone call to offer condolences and support.
9pm: Martin Griffiths, the UN's Undersecretary General for Humanitarian Affairs, revealed he had released $25 million from its Central Emergency Response Fund for victims of the quake.
10pm: A UK team of 77 search and rescue specialists, four sniffer dogs and equipment arrived in Gaziantep in south-eastern Turkey to join the earthquake emergency response. Twenty-eight rescue teams were sent from 19 EU countries, as well as Albania and Montenegro.
10pm: UN figures showed that about 6,000 buildings in Turkey had been damaged or demolished, with at least 250,000 people estimated to be homeless.
12.10am: British Prime Minister Rishi Sunak said he had spoken to Mr Erdogan on Tuesday, expressing his deep condolences for the tragic loss of life and pledging the UK’s steadfast support. King Charles III told the Turkish President his “thoughts and special prayers” were with all those affected by the earthquakes.
3am: A statement by Mr El Sisi revealed that Egypt had on Tuesday sent five planeloads of medical supplies to help earthquake survivors.
7am: It was revealed the death toll from the earthquake had risen to almost 8,000, with rescue workers still searching for trapped survivors, as the first aid from the UAE arrived in Syria, where almost 2,000 people have been killed.
Midday: Turkey's disaster and emergency service released figures showing 6,957 people had been killed and 38,224 injured in the country, 648 aftershocks had been recorded since the initial earthquake, 96,770 personnel were working in disaster zones, 5,309 foreign workers were participating and 92,738 tents and 300,000 blankets had been sent.
Midday: The Turkey-Syria earthquake was revealed to be the deadliest in a decade as the death toll approached 10,000. As well as at least 6,957 killed in Turkey, more than 2,500 were reported dead in Syria.
1pm: The US steps up support, with 100 firefighters from California set to join relief efforts, joining thousands of specialists from outside Europe including search and rescue teams from Russia, China, India, Mexico, as well as the Middle East, where Saudi Arabia, the UAE, Kuwait, Jordan and Iraq are among countries mobilising "air bridges" of aid.
3pm: Turkish President Recep Tayyip Erdogan says there were issues with the initial response to the earthquake. Turkish Airlines says it has evacuated more than 19,000 people with plans to evacuate 30,000 more.
4pm: Aid has entered Syria from Iraq through the Al Bukamal crossing. A team of Egyptian emergency workers arrive in north-western Syria to assist the White Helmets and other groups in rescue efforts.
5pm: The Turkish President visits a football stadium in Onikisubat district, where a tent was set up to shelter survivors. He later arrives in Pazarcik, one of the earthquake's two epicentres.
6pm: Syria receives 20 tonnes of medical aid and supplies from Egypt through Damascus International Airport. The death toll has risen to 9,057 in Turkey, President Recep Tayyip Erdogan says. The UAE airlifts three injured Emiratis from quake-hit areas in Turkey.
9pm: Emirates Red Crescent launches a two-week volunteer drive to help earthquake survivors.
10pm: American search and rescue teams arrive in Turkey from the US Agency for International Development. An aid flight leaves Dubai carrying medical aid enough for 23 million people bound for Istanbul.
3am: UK disasters committee launches charity appeal for Turkey and Syria as the total death toll rises above 12,000 across Turkey and Syria. The UK also sends essential aid to Turkey and Syria including medical kits, tents and blankets as well as a team of 76 search-and-rescue specialists.
4am: India says it will send 50 more relief workers to Turkey to help on the ground after about 150 emergency workers and paramedics as well as 129 tonnes of aid had already reached the country. Ten Indians were stuck in quake-hit areas in Turkey, authorities said. Unicef has said it is running out of trauma supplies in Syria. Sheikh Sultan bin Tahnoon, chairman of the board of directors of the Frontline Heroes Office, praises first responders from the UAE who are helping in disaster relief efforts.
8am: The EU pledges more support to Turkey and Syria worth $7 million. Taiwan's president and vice president promise to donate a month's salary for Turkish earthquake relief efforts. Saudi Arabia raises more than $16 million in donations to help survivors in Turkey and Syria.
9am: At least 16 babies have been evacuated from the earthquake's epicentre in Turkey as Adiyaman province runs out of body bags, a doctor has said.
11am: A Palestinian family who fled violence in Gaza are found dead in Turkey. Humanitarian aid to north-west Syria has not yet arrived even after border crossings opened.
12pm: About 450,000 shelters are open across southern Turkey the Education Ministry has said.
2pm: The death toll passed 17,000 in Turkey and Syria. Oman and Bahrain are sending aid to the countries.
3pm: A river has flooded in north-west Syria, causing residents to flee after the Maydanki dam was breached and the Asi burst its banks. UAE President Sheikh Mohamed calls for prayers for earthquake victims.
7pm: The UAE says it rescued a Syrian family from under the rubble of their home in Turkey.
10pm: A Saudi plane carrying 98 tonnes of relief lands at Turkey's Adana airport. Two Emirati aircraft carrying 111 tonnes of humanitarian assistance arrived at Damascus Airport. Pope Francis has appealed for unity in the disaster's aftermath. The death toll crosses 19,000.