Follow the latest news on the earthquake in Turkey and Syria
A million people are believed to be living in temporary shelters after the earthquake in Turkey as fears grow about the spread of disease.
About 80,000 are being treated in hospital, putting a further strain on a healthcare system that has been badly damaged by the disaster, said Hans Kluge, the World Health Organisation's regional director for Europe.
On Tuesday, he described the earthquake that struck Turkey and Syria as the worst natural disaster in the region for more than a century.
WHO charter flights to Turkey and Syria have taken medical kits that will allow healthcare workers to treat about 400,000 people, while Turkey is to distribute vaccines to guard against tetanus and rabies.
"Just over a week since this terrible tragedy, there are growing concerns over emerging health issues linked to the cold weather, hygiene and sanitation, and the spread of infectious diseases," Mr Kluge said.
"Water and sanitation facilities are also hit. We are increasing public health surveillance and have to be ready for communicable disease outbreaks."
The charity Save the Children has said young people are particularly vulnerable to waterborne diseases.
There have been reports of children falling ill in shelters.
"People in the earthquake-affected areas urgently need safe drinking water and latrines," said Marielle Snel, a hygiene and sanitation adviser for the charity.
The death toll from the earthquake passed 35,500 on Tuesday, most of them recorded in Turkey.
About 2,200 have died in rebel-held areas of northern Syria, while the government in Damascus has reported 1,400 deaths in territory under its control.
The UN said two crossing points were opened between Turkey and Syria, easing the diplomatic headache of bringing aid into Syrian territory.
Earthquake in Turkey and Syria - in pictures
-
A woman walks among destroyed buildings in Hatay, Turkey. Getty Images -
A woman mourns a relative during the burial of one of the earthquake victims in Antakya, southeastern Turkey. AP Photo -
A family photo is seen amid the rubble in Hatay. Getty Images -
Syrian refugees in Turkey return to their home country following the deadly earthquake. AFP -
Members of NGOs Deathcare Embalming Team and Turkish Kurt-Ar inspect the bucket of an excavator as they search for bodies in Kahramanmaras, Turkey. AP Photo -
Dust covers a family photo album found in Antakya. AP Photo -
A man made homeless by the 7.8-magnitude quake carries mattresses distributed by an NGO at a makeshift camp in Afrin, in Syria's Aleppo province. AFP -
A cracked road near the quake’s epicentre in Kahramanmaras, Turkey. AFP -
A rescuer stands near the site where Aleyna Olmez, 17, was rescued from the rubble of a collapsed building in Kahramanmaras, about 10 days after the quake struck. AFP -
A rescuer holds a cat after it was rescued from the ruins of a collapsed building in Kahramanmaras. AFP -
Quake survivors queue for food amid the rubble in Kahramanmaras. Reuters -
Bedran, a local resident who lost his house in the earthquake, keeps warm in Antakya, Turkey. Reuters -
A girl carries a box of water bottles next to a damaged mosque in Antakya. Reuters -
A car lies crushed by parts of a badly damaged building in Samandag, Turkey. AP -
Residentes remove their belongings from their destroyed house in Samandag. AP -
Aleyna Olmez, 17, is rescued after being trapped for 10 days in Kahramanmaras. Getty -
Turkish Foreign Minister Mevlut Cavusoglu, left, with Nato Secretary General Jens Stoltenberg in Ankara. AFP -
A message scrawled on a car covered in dust from collapsed buildings in Antakya, Turkey. AP -
Destruction in Antakya. AP -
A cracked road leads to a flooded area in Antakya. AP -
A man looks bewildered at the site of collapsed buildings in Hatay, Turkey. EPA -
Numbered stones near graves of earthquake victims at a cemetery in Adiyaman, Turkey. EPA -
A makeshift camp set up amid the rubble in Antakya, south of Hatay. AFP -
A woman holds her baby inside a tent in a camp in Antakya, Hatay. AFP -
Greek and Turkish rescuers are at work to extract bodies of victims from the rubble in Antakya. AFP -
Samar Hamouda, 44, recalls her experience of the earthquake destroying her home, at Tishreen Hospital in Latakia, Syria. Reuters -
A damaged house in Jableh, Syria. Reuters -
Photos of missing children left in hope in Kahramanmaras, Turkey. Reuters -
People collect copies of holy books from the rubble in Kahramanmaras. Reuters -
Rescuers search for survivors under the rubble of a collapsed building in Kahramanmaras. Reuters -
People carry a bodybag as residents wait for their relatives to be pulled out from the rubble in Hatay. AFP -
Dust covers a family photo album found in the debris of a building in Antakya. AP -
Portuguese rescue team members try to free the dog named Tarcin from the rubble in Antakya in Hatay. EPA -
An injured survivor at a makeshift hospital set up at Turkish Bayraktar warship anchored near Iskenderun city, southern Turkey. AP -
A makeshift hospital set up at Turkish Bayraktar warship anchored near Iskenderun city, southern Turkey. AP -
Britain's King Charles III (C) meets with members of the Turkish diaspora community who have been collecting, packaging and organising the transportation of food, blankets and warm clothing for people who have recently been affected by the earthquakes in Turkey and Syria, during a visit to the West London Turkish Volunteers, in Hounslow, greater London. AFP -
People stand by the fire next to the ruins of a collapsed building in Elbistan, Turkey. Reuters -
Destroyed buildings in Syria's rebel-held village of Atarib, in the north-western Aleppo province. AFP -
Rescuers carry Fatma, 15, who was pulled out from the rubble in Hatay, Turkey. Reuters -
A displaced woman receives food inside a stadium in Kahramanmaras, Turkey. Reuters -
People lineup to receive aid supplies at a makeshift camp in Iskenderun city in southern Turkey. AP -
Humanitarian aid provided by Saudi Arabia for survivors of the February 6 earthquake are unloaded at Aleppo Airport in northern Syria. AFP -
Turkish President Recep Tayyip Erdogan addresses the World Government Summit in Dubai via video link. Antonie Robertson/The National -
A man walks between trains being using as shelters in Iskenderun, southern Turkey. AP Photo -
A woman and children inside a train being used as shelter after the earthquake, in Iskenderun. AP Photo -
Tents erected in a school yard for Syrians who have lost their homes after the deadly quake, in the rebel-held town of Harem in Syria. Reuters -
A woman walks by the destroyed Habib-i Neccar mosque in the historic southern city of Antakya in Hatay, Turkey. AFP -
Rescuers pull out a 12-year-old Syrian girl, Cudi, from the rubble in Hatay. AFP -
Amar, a Syrian refugee living in Turkey, looks on as search for survivors continues in Kahramanmaras. Reuters -
Displaced people keep warm by a fire in Kahramanmaras, Turkey. Reuters -
Earthquake survivors receive distributed meals in Golbasi, Turkey. AP -
A woman stands amid boxes of donated clothes in Golbasi, Turkey. AP -
A man walks near a damaged building that leans on a neighbouring house in Golbasi, Turkey. AP -
UN emergency relief co-ordinator Martin Griffiths stands amid quake-damaged buildings in Aleppo, Syria. Reuters -
Delegates observe a moment of silence for the Turkey–Syria earthquake before the start of the World Government Summit in Dubai. Pawan Singh / The National -
People keep warm by a fire as the search for survivors continues a week after the earthquake in Kahramanmaras, Turkey. Reuters -
A child receives food in Kahramanmaras, Turkey. Reuters -
A dog is seen through a glass door in Kahramanmaras, Turkey. Reuters -
Children walk in the street with food boxes in Kahramanmaras, Turkey. Reuters -
A minaret stands as the sun rises over the earthquake-hit city of Kahramanmaras, Turkey. Reuters
Mr Kluge said an initial WHO appeal for $43 million to support its earthquake response was likely to "at least double" as the scale of the disaster becomes clearer.
Some of those affected by the tremor are Syrian refugees in Turkey who have "lost everything again", Mr Kluge said.
"Now is the time for the international community to show the same generosity that Turkey has shown to other nations globally over the years," he said.
The earthquake's "true cost is not known yet. Recovering and healing will take time and a phenomenal effort".
The WHO sent 22 medical teams to support the Turkish health system and treat trauma patients with serious injuries.
Search and rescue teams are still examining the disaster zone eight days after the 7.8-magnitude earthquake, but hopes are fading that more survivors will be found.
