MANILA (AFP) - A huge fire that swept through a crowded Manila shanty town has razed more than 800 homes, leaving thousands homeless after they were forced to flee for their lives from the towering flames, officials said on Thursday (Nov 26).

Residents joined forces with firefighters to battle Wednesday's (Nov 25) blaze which spread quickly among the narrow alleys, helping smash down the walls of makeshift houses to allow crews access to the flames.

People evacuated their homes carrying young children and whatever possessions they could salvage, with thousands forced to seek shelter in makeshift tents at a local park.

Despite the devastation, no one was killed in the disaster and only four people were injured as they clambered over their homes to escape, authorities said.

Desperate locals called out "over here, over here" to a military helicopter which was drafted in to dump water on the blaze, after fire engines could not reach the heart of the inferno in the sprawling shanty town.

"The alleys were too narrow and people were rushing out. Even worse, the wind was strong and fanned the flames," said chief fire marshall Nahum Vitarosa.

He added that deaths were avoided because the fire broke out in the afternoon when residents were able to evacuate quickly.

"If it happened at night, it would have been a real tragedy. People would have been left behind in the dark," he added.

Residents are also used to coping with fires which break out frequently in shanty towns, although rarely on this scale, Vitarosa said.

The cause of the fire is still under investigation but Vitarosa said authorities suspected a short circuit, possibly from an illegal connection to power lines.

He added that about 2,000 families had been forced to seek shelter in a public park, a gym and a school while authorities looked for emergency housing.

Manicurist Matilde Agustin, 59, said she narrowly escaped with her daughter-in-law and four grandchildren as the blaze engulfed their home.

"We rushed out as soon as we could," she said, adding she fled carrying her youngest grandchild, a one-year-old girl.

The family only managed to salvage a few meagre possessions including some clothes and a small statue of the infant Jesus, she told AFP.

Her son Rommel Agustin, a labourer, was now going through the ruins, trying to find scrap metal he could sell but the rubble was still smoking, she added.

The family was sheltering under a makeshift tent at a public park along with hundreds of other residents surviving on government food handouts.

"It is shameful that we have to celebrate Christmas like this... but it is okay that almost nothing was saved as long as no one was hurt," she said.

Fires in shanty towns, where homes are made of little more than scrap wood, are common in Manila - a metropolis of more than 11 million people - but Vitarosa said this was the worst such fire he had seen in five years.