By Oliver Tree and Vasudevan Sridharan

This is the dramatic footage of a Syrian army helicopter crashing to the ground after being shot down by rebel forces, it was claimed Monday.

The amateur video, courtesy of Russia Today, shows the government helicopter on fire after being hit by what Free Syrian Army Forces claim was a missile fired by one of their own, Reuters reported.

"It was flying overhead the eastern part of the city and firing all morning. The rebels had been trying to hit it for about an hour, and finally they did," said Abu Bakr, a local activist.

The news comes as it emerged President Bashar al-Assad's forces have reportedly slaughtered more people in Daraya town, near the capital, Damascus, than it was earlier feared.

Latest reports emerging from the region show more dead bodies being discovered, which may range anywhere between 300 and 600. Initially, the death toll was thought to be around 200, which by itself is one of the highest in the 17-month-long uprising against the regime.

Most of the victims were shot in their chest and head indicating execution-style massacre.

If the reports turn out to be true, this will surpass all the bloodiest mass killings in Syria.

It is unclear when the massacre took place. Describing the killings, residents say the forces encircled the whole area to prevent civilians from fleeing the town followed by targeted shelling. Thereafter, Assad's troops are believed to have conducted house-to-house raids to carry on slaughtering the remaining.

Gruesome videos have surfaced online showing the scale of carnage undertaken by Assad's forces. In one of the unverified videos, men believed to be of Assad, mercilessly torture captured rebels including children.

Another video shows several bodies of children who were shot in their head lined up. Many of the victims appear to be quite young.

Mass burials of the massacre victims have been undertaken in the Sunni-dominated Daraya town. Before the burial, the bodies were washed by hoses, and blood-soaked bodies wrapped in blankets were lined up closely next to each other.

Assad appears to be in no mood to halt the bloodshed until the very end, suggests a new report.

"It is clear that was collective punishment. I am certain that the coming days will reveal more massacre, but by then others will have taken place and people will forget about Daraya," an activist from Damascus, Khaled al-Shami, told the Press Association.

Daraya, with a population of around 200,000 and the closest town to Damascus, was one of the first few regions to protest against the regime during the early days of the uprising.