Three people were killed and three others were wounded early Sunday in clashes in Yemen's second largest city Taez, a tribal source said, amid an uneasy calm in the capital a day after deadly clashes.

The overnight fighting erupted between armed tribesmen who have thrown their support behind anti-government protesters and security forces loyal to embattled President Ali Abdullah Saleh.

Two tribesmen were killed and three others were wounded, a tribal source told AFP, requesting anonymity.

A medical official in Taez said a third man was shot dead early on Sunday by government troops.

The clashes came a day after security forces, including the elite Republican Guard troops commanded by Saleh's son Ahmed, bolstered their deployment throughout Sanaa.

Residents and tribal sources said troops with heavy weapons and armoured vehicles have positioned themselves throughout the city and on hilltops around the capital.

The deployment came after Saleh's return to Yemen on Friday after a near four-month absence. He flew in from Saudi Arabia where he received treatment for wounds sustained in a June explosion at his presidential compound.

Taez has been the scene of intense clashes between government troops and anti-regime protesters since calls for Saleh's resignation began in January.

In June, influential tribal leaders deployed armed men to protect pro-democracy protesters in the city, leading to regular firefights and bloody clashes between the two sides.

At least eight people in Taez have been killed in the past week, six of them civilians, according to medical officials.

Meanwhile, calm prevailed in Sanaa after a bloody week of clashes left more than 170 people dead, mostly unarmed protesters.

The streets of the capital were eerily silent overnight and remained so throughout the morning Sunday, in stark contrast to the constant gunfire and explosions that have rocked the capital, especially since Friday.

Saleh is expected to give a speech later Sunday to mark the 49th anniversary of the September 26, 1962 revolution that saw Yemen proclaimed a republic, although no appearance has been officially announced.