Assad's forces storm central district of Damascus.

Reuters - Elite Syrian forces backed by armoured personnel carriers stormed part of Damascus on Wednesday, firing machineguns in the air, in the closest deployment of troops to the centre of the capital in an 11-month uprising, residents and activists said.

Troops from the Fourth Armoured Division and Republican Guards erected roadblocks in main streets of Barzeh neighbourhood, a residential neighbourhood north of the city centre, searched houses and made arrests.

Residents said the troops were looking for opposition activists and members of the rebel Free Syrian Army, which has been providing security for protests against President Bashar al-Assad in the district.

"They have destroyed the facades of shops and turned back students heading to school. The raids are concentrating on Dahar al-Mustaha and Haret al-Bustan," Mazen, a university student, said by phone from Barzeh.

He said at least 1,000 soldiers had deployed in the district after seeling off its thoroughfares, along with armoured personnel carriers, armoured jeeps and pick-up trucks with heavy machineguns mounted on them.

The largely Sunni Muslim district has been among the most active in the capital in the protest movement against the 42- year rule of Bashar al-Asssad and his father, the late President Hafez al-Assad.

Pro-Assad militiamen from an Alawite suburb in a mountains overlooking Barzeh have managed to suppress the demonstrations for months until the Free Syrian Army began protecting them in the last several weeks, residents said.

A firefight erupted last week in Qaboun neighbourhood, which is adjacent to Barzeh between loyalist forces and Free Syrian Army fighters, indicating the emergence of armed opposition to Assad inside the centre of his rule.