Syrian troops have attacked two towns north of the capital Damascus, as they continue a crackdown against anti-government protests, reports say.

Witnesses said the troops - backed by tanks and helicopters - surrounded and cut off the towns of Rastan and Talbisa early on Sunday.

Some reports say two people were killed as houses were stormed.

Human rights groups say more than 1,000 people have been killed in Syria since the uprising began in March.

Syria has banned foreign journalists, making it difficult to verify eyewitness accounts. Syrian authorities insist they are pursuing "armed terrorist gangs".

The two towns attacked on Sunday are close to Homs, the site of some of the largest demonstrations in recent weeks.

Tanks encircled Rastan and troops began firing heavy machine-guns in the streets of the town, an eyewitness told Reuters news agency. (read more)