Heavy shooting as Syrian army locks down Damascus suburb

Security forces are also continuing their efforts to crush anti-government protests in the central city of Homs, Deraa and the coastal town of Baniyas. On Sunday, there were reports from Homs of gunfire, arrests and deaths, including that of a 12-year-old boy.

Meanwhile, more security forces were reported to be moving into the central city of Homs, north of Damascus, where troops backed by tanks have been raiding houses and arresting people since Saturday night.

The UK-based Syrian Observatory for Human Rights said on Sunday that the areas of Bab Sebaa, Bab Amro and Tal al-Sour were under "total siege", and that hundreds had been arrested. The number of casualties was unknown, it added.

Some 15 people were said to have been shot dead in Homs on Friday after taking part in demonstrations following Friday prayers.

Activists said hundreds were arrested in Baniyas on Sunday, including a 10-year-old boy. On Saturday, soldiers shot dead four women taking part in a small all-women demonstration near the city, they added.

In Deraa, which has been under military occupation for two weeks and where scores of protesters have been killed, residents were allowed out for a few hours to buy supplies before a curfew was imposed.

The Syrian human rights group, Sawasiah, believes more than 800 people have been killed since pro-democracy protests began in March, including 220 killed in an army assault on Deraa. The US has said the crackdown is "deplorable" and pledged a "strong international response".

Foreign journalists have not been allowed to enter Syria, so the reports are difficult to verify independently.