Follow the latest news from the Sudan crisis here
British families have been making pleas for help to find their relatives and evacuate them from Sudan amid accusations many have been abandoned by government rescue efforts.
A number of nations have completed operations to remove their citizens from the country as fighting raged for a 10th day between forces loyal to two rival generals.
Clashes between army and paramilitary forces have led to people being trapped indoors, enduring acute shortages of water, food, medicine and fuel as well as power and internet blackouts, the UN said.
British doctor Javid Abdelmoneim, a former UK president of the humanitarian organisation Doctors Without Borders (MSF), has been trying to organise the rescue of his elderly father.
He was last in touch with the 80 year old at the weekend and his father had chosen to stay in Sudan on the advice of the British embassy, the doctor said.
Dr Abdelmoneim criticised the British government for the “avoidable” situation his father is now in.
"With the expectation of a UK evacuation, my dad declined a family invite to travel overland to Egypt and skipped another family convoy to Port Sudan," he tweeted.
"It transpires, the UK evacuation had happened 18hrs previously, in secrecy, and actively reduced his chances of reaching safety. The UK government communication, both public and private to my dad and sister, has actively reduced the chances of him reaching safety. Enough said."
With the communication networks down, he now fears for his father's safety.
"Window of opportunity for my dad to leave Sudan safely is closing, a matter of hours now, as my last two family groups plan their departure today," he said.
"Internet down, international calls blocked, local network patchy. We have no way of knowing that he can get to them. All this [was] avoidable."
Iman Abugarga, a British woman who has been sheltering in Khartoum, said she feels abandoned by the British government.
“It is shameful how they have mismanaged this situation,” she told the Telegraph.
The UK government's response to fighting in Sudan is under increasing scrutiny, with the Foreign Office accused of abandoning British civilians and failing to learn lessons from the evacuation of Kabul.
William, a UK citizen in Sudan, told the BBC he was forced to “go private” to leave Khartoum on a bus arranged by his Sudanese employer because “we’ve had absolutely nothing but nonsense from the government”.
British citizen Jim Gardoufy, who managed to get out of Khartoum, defended the government.
“I'm a British national currently in Sudan,” he said.
“Thankfully, I was able to get out of Khartoum and am in another state. The fact of the matter is it would be very difficult to co-ordinate a mass evacuation of citizens. You'd likely need them to meet en masse at a specific location.”
London doctor Shaza Faycal’s young children, brother and mother are stuck in Khartoum after travelling to the Sudanese capital to celebrate Eid Al Fitr.
She said she was “quite stressed” and called for help to get British citizens home.
British-Sudanese woman Rozan Ahmed is trapped in Khartoum after travelling to the country to attend a funeral.
“I have been hiding under my bed for the last six hours, the area where I stay has been shelled to shreds,” she told Sky News.
Clashes continue in Sudan's capital, cutting residents' basic supplies
“I have heard nothing but explosions and gunfire. On top of that, we have to deal with rogue soldiers walking around our streets, raiding our homes, and then we don’t have water.
“This has been the most harrowing experience of my life and my only focus right now is to get to my mother, who is probably more pained than I am.”
Elmugiera Hafazalla, a 56-year-old delivery driver and medical translator from Manchester, is trapped in Khartoum after flying out for a family wedding.
“He's all right, but they've been advised to stay indoors, so he's not really leaving the apartment,” his son Hakim, 24, told the Manchester Evening News.
“There's no reliable running water, so he's only going outside to get groceries and water.
“There's been a lot of shelling in the area where they are staying. It's literally on their doorstep. A neighbour's windows were blown in by the shock waves and in the video you can see the impact from where a shell has hit the apartments.
“He's trying to find a way out of the country. He considered trying to cross into Egypt but apparently the border is not very safe right now.”
At least 427 people have been killed and more than 3,700 wounded to date, according to UN agencies, which also reported Sudanese civilians “fleeing areas affected by fighting, including to Chad, Egypt and South Sudan”.
More than 4,000 British citizens could still be stuck in Sudan awaiting evacuation, said Alicia Kearns, chairwoman of the UK’s Foreign Affairs Select Committee.
She said people in Sudan were “terrified” and living in “abject fear”, most of them with little water and food left.
