UN demands access to Yarmouk refugee camp in Damascus
The UN Security Council has demanded humanitarian access to the Palestinian refugee camp of Yarmouk in Damascus.
One UN official described the situation for the 18,000 refugees there as "beyond inhumane".
The situation has deteriorated since 1 April, when Islamic State (IS) fighters launched an offensive.
Palestinian militiamen opposed to the Syrian government and some Free Syrian Army fighters are leading the fight against IS.
'Die or leave'
The chair of the 15-member Security Council, Jordan's ambassador Dina Kawar, called for the protection of civilians, humanitarian access and life-saving assistance.
Delivering a report to the council, Pierre Krahenbuhl of the Palestinian Unwra relief agency said the situation was "more desperate than ever".
The Palestinian UN ambassador, Riyad Mansour, said that saving the refugees was his government's main priority.
He appealed to member nations to relocate the refugees elsewhere in Syria or abroad.
A few hundred people were reported to have managed to escape the camp over the weekend.
One woman told BBC Arabic she fled alongside her brothers, one of whom is paraplegic.
"We were stranded inside our homes, we could hear the exchange of fire. We were really scared," she said.
"The only solution we faced was either die there or leave the camp, but we managed to escape in a matter of minutes.
"I consider all the occupants of the camp as members of my family. The only place we call home is this camp, not Palestine nor Syria. All the children here are my children, young and old. They're fathers and sons to me.
"We don't know why we have done to deserve this. We are now displaced once again."
At the scene: Assaf Abboud, BBC Arabic
We are in the middle of Yarmouk Camp in the neighbourhood of Ali Alkharboush. This area represents a battleground and snipers are everywhere.
While walking around we didn't see any civilians, mainly due to the large evacuations of refugees from the camp. As many as 2,000 have fled in the last five days.
The factions fighting Islamic State are trying to evacuate the remaining population, but snipers are targeting Yarmouk's main exits.
Clashes continue in several areas especially at the point where IS originally entered the camp. But we didn't hear any explosions or gunfire.
Ahmed Majdalani, an official with the Palestine Liberation Organisation, said a delegation was on its way to Damascus to discuss a humanitarian corridor with the Syrian government and Palestinian factions in the camp.
Another Unwra official, Chris Gunness, said: "The situation in the camp is beyond inhumane.
"There is no food, there is no water and there is very little medicine... People are holed up in their houses, there is fighting going on in the streets. There are reports of... bombardments. This has to stop and civilians must be evacuated."
It was impossible to deliver aid as humanitarian workers and civilians are coming under fire, said a spokesperson for the charity Save the Children.
Sunday's heavy fighting turned into sporadic clashes on Monday, monitors said.
Monitors say IS and the al-Qaeda-affiliated Nusra Front, who have fought each other in other parts of Syria, are working together in Yarmouk.
Syria's bloody conflict, which has entered its fifth year, has claimed the lives of more than 200,000 Syrians.
The battle between forces loyal to President Bashar al-Assad, rebels opposed to his rule and Islamic State has also driven more than 11 million people from their homes.
Yarmouk was first built for Palestinians fleeing the 1948 Arab-Israeli war.
Before the Syrian civil war began, it had more than 150,000 refugees living there and had its own mosques, schools and public buildings. But since 2012, the camp has been besieged by fighting.