* Jihadists who took camp last year now fighting each other
* U.N. unable to deliver aid to Yarmouk camp on Damascus outskirts
* Residents run sniper gauntlet to fetch food from nearby town
* Tens of thousands have fled Palestinian camp
By John Davison
BEIRUT, June 8 (Reuters) - Palestinians living in Yarmouk refugee camp on the southern outskirts of Damascus depend on food aid to survive the Syrian civil war. But collecting it can be lethal.
With Islamic State and al Qaeda affiliate Nusra Front fighting each other for control of the camp, the United Nations has been unable to deliver food for more than a year and has to distribute it in neighbouring areas instead.
On the journey to the collection point, tarpaulins hung between buildings offer the only protection in some areas keeping residents out of the sights of snipers, who often fail to distinguish between fighters and non-combatants.
Once the camp residents have run this gauntlet, they still have to get through an Islamic State checkpoint. This controls the way out to the nearby town of Yalda, where the U.N. Palestinian refugee agency UNRWA and other groups hand out aid when they can.
One 22-year-old resident who called himself Mahmoud - although he said this was an alias due to the risk of reprisals by the militants - described via internet messages how he makes the trip three times a week.
"I leave my house, and about a kilometre away there's the checkpoint," he told Reuters. "Most streets in the camp are in the sights of snipers, from both sides - I have to watch out for them. Some streets I run down, some I can just walk."
While tens of thousands have fled the camp since the war began, hundreds of residents still brave the same journey.
The camp has existed for decades, one of many set up in the region after the 1948 Arab-Israeli war for Palestinians who fled or were expelled from their homes. Today they largely accommodate descendents of the original refugees, although some Syrians displaced by the war have inhabited Yarmouk.
Yarmouk has been bombarded, besieged and isolated from the outside world since early in the multi-sided conflict, which is now in its sixth year. Government forces, rebels and jihadists have all fought for control of the camp that lies just a few kilometres (miles) from the heart of Damascus.
NO MAN'S LAND
Islamic State entered the densely built up Yarmouk in April last year, helped by Nusra Front fighters in a rare instance of cooperation between the jihadist rivals, capturing most of it.
Since then they have turned their guns on each other, and fighting in recent weeks has destroyed countless more homes as Islamic State tries to take areas held by Nusra Front.
"Things got worse recently. This is a fight taking place only inside the camp, not spreading out to another area - it's concentrated," said Mahmoud. Fighters were targeting houses and burning them, even with occupants still inside, to hamper advances by the other side, he added.
Across a strip of no man's land from Islamic State territory, rebels fighting under the banner of the Free Syrian Army control Yalda.
"The route to Yalda is more or less dangerous depending on how heavy the clashes are. Lately, people living in the fighting hotspots have to move around behind tarpaulin curtains and banks of earth," said Yousef, who like all the Yarmouk residents interviewed by Reuters also asked to use an alias.
"Last Thursday, someone got shot by a sniper," said Yousef.
Mohammed, 30, who before the latest violence sold food from a street stall, said: "If someone leaves their house to get a bit of water, they might not come back. Getting bread, getting food, could cost someone their life."
FRAGILE AID SUPPLY
Islamic State controls at least two-thirds of Yarmouk and has been trying to prise the rest from Nusra Front since April, monitoring group the Syrian Observatory for Human Rights said, adding that several civilians have been killed in recent weeks.
Many do not venture out. "Most people just sit at home ... we're stuck here and stuck in the camp," said Abu Anas, a former manual labourer.
"There's very little water, and little fuel. We chiefly rely on aid from UNRWA. It's not much but it's our best hope - every 20 days we get a parcel which is just about enough for a family." These include around 4 kg (9 pounds) of lentils, 5 kg of sugar, 1 kg of pasta and tins of tomatoes, he said.
Fighting can close the checkpoint for days at a time. But if they can get through, Mahmoud, Yousef and their fellow residents also buy any extra provisions they can afford at market stalls in Yalda, before returning.
Even getting aid the few kilometres from Damascus to Yalda, through government and then rebel-held territory, requires painstaking talks with local authorities, community leaders and commanders of the warring sides.
"When we first had access to Yalda, just to get there the U.N. had to negotiate 17 separate agreements," UNRWA spokesman Chris Gunness said. For at least a month beginning in April, UNRWA could not even reach Yalda, and warned that residents faced starvation until supplies resumed.
"Inside Yarmouk, the fighting forces have been using indiscriminately large munitions," Gunness said. "For a U.N.-assisted population in the 21st century to find itself in this situation in the capital city of a U.N. member state is completely unacceptable."
Frequent power and water supply cuts mean people have to rely on generators and drinking water sold from the back of trucks which residents bring in by a different route. Water from wells - many of them hard to reach because of the fighting - is polluted and can be used only for washing, Yousef said.
Among the thousands who have joined the exodus from Yarmouk, some have sought refuge inside Syria with others heading to neighbouring countries or Europe.
An aid worker for the Jafra Foundation, which monitors human rights in Palestinian camps in Syria, said several hundred people had left Yarmouk in recent weeks alone.
The camp's pre-war Palestinian population of 160,000 has plunged to between 3,000 and 6,000 residents. At least the same number of displaced from the camp also live in Yalda, he said.
Mahmoud, who said his mother was killed in shelling by government forces three years ago, will stay.
"My home is here and my dad lives here. When I go to Yalda, I feel like a displaced person," he said. "Yarmouk is my camp, I can't leave it." (editing by David Stamp)
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