The amber light of the street lamp illuminates the boy, wrapped in a thin blanket, his legs exposed to the December cold as he sleeps by a kerbside in a wealthy district of Damascus.

The child - barely in his teens, if that - was said by the opposition activist who posted his photograph on the Internet to be from Yarmouk, a Palestinian district near the city centre which has become the latest battlefield for rebels and a target for President Bashar al-Assad's artillery.

Syria hosts half a million Palestinians, refugees who fled at the creation of Israel in 1948 and their descendants. Most are housed in the densely-built apartment blocks of Yarmouk.

As rebels took the area late on Monday evening, retaliatory strikes from government forces came hard and fast. Fleeing residents said they ran, many on foot, as high-explosive and hot metal destroyed their homes.

Several thousand jumped into taxis and buses and fled for the Lebanese border, 50 km (30 miles) away. Others had friends and families who could offer support. But after 21 months of conflict, many were out of money and out of options.

Residents of Damascus speak of hundreds of families stumbling into the wide boulevards of hitherto affluent central Damascus, looking dazed as they sit in parks and on pavements.

One woman who lives there told Reuters the Palestinians appeared to be in disbelief at their own fate: "I was trying to get a taxi when I saw a dazed old man on the pavement," she said, asking not to be named for fear of official retribution.

The man, well dressed in a blue jacket, was trying to cover himself in newspapers to protect his body from the cold: "He couldn't get his legs covered because he didn't have enough newspapers. He wrapped his hands around his head to keep warm."

Another resident said that the displaced have set up Palestinian communities around the city's central districts, areas that are firmly in government control and - unlike the rebel-infiltrated outer suburbs - will not be bombed.

"There is a park just opposite the Four Seasons hotel. It's become a place for many families," this second woman said.

"I was walking past there and a little boy, about 10 or 11, asked me if there were any jobs he could do," she added.

The boy took her into the small park and, under a tree, his 18-month-old brother was sleeping in a cardboard box.

"What happened in Yarmouk was so sudden that citizens decided to flee in a split-second decision," she said.

"They took nothing with them."

GOVERNMENT-RUN AID

The Syrian government severely hampers independent media organisations, so it is difficult to verify reports.

Assad and his father before him have for 40 years cast Syria as champion of the Palestinian cause. But during the crackdown and war in which 40,000 people have been killed Assad has lost most of his Palestinian allies.

The leadership of Palestinian Islamist movement Hamas, whose religion and politics are more aligned with the rebels, decamped from Damascus for Qatar, one of Assad's fiercest foes.

Overall, some 2.5 million people have already fled their homes in Syria and it is possible the government has run out of shelters or was overwhelmed by the latest sudden surge.

Lisa Gilliam, an official at UNRWA, the U.N. agency that helps Palestinians, said as many as 100,000 of them were on the move. Aid workers were offering food and shelter, she added: "But for the most part we don't know where they are."

Syria restricts access for international relief groups and the United Nations relies on the local Syrian Arab Red Crescent (SARC) to distribute its aid. But many of the displaced see local humanitarian workers as allies of Assad's government.

Some locals accuse SARC staff of acting as informers and limiting what aid they give to residents of rebel-held areas, such as Yarmouk, essentially helping the army enforce collective punishment. Others blame rebels for limiting SARC movements, saying fighters sometimes attack the SARC convoys.

As rebels move into more areas around the capital, central Damascus is one of the last safe havens in the embattled city.

A caption on the picture of the boy sleeping on the streets says it was taken in the wealthy district of Abu Ramaneh. Nearby is the Ummayad Square, which is to Damascus what Trafalgar Square is to London or what Times Square is to New York.

He, like thousands of others, will sleep outside in city where overnight temperatures plummet close to freezing in winter. Wednesday was bright but rain is on the way.