Defiant protest marches unfolded across the country despite a military crackdown that has triggered sanctions and condemnation abroad.

These included protests in the cities of Hama and Deir Al-Zour, both of which have been stormed in tank offensives launched by Assad during Ramadan.

The Local Coordination Committees activists said among the deaths were six in the Damascus suburbs of Saqba and Douma, two protesters killed in the commercial hub of Aleppo, and two in the northern province of Idlib on the Turkish border.

Residents said two people were also killed in Hama, just days after the army completed a week-long assault on the city which became a symbol of defiance to Assad's rule after huge crowds gathered weekly to demand his overthrow.

"Go, Bashar!" protesters chanted in rallies held in the coastal cities of Latakia and Baniyas, as well as across the southern province of Deraa where the uprising against 41 years of Assad family domination first flared nearly five months ago.

In Deir Al-Zour, forces fired live ammunition at protesters coming out of a main mosque, killing one person according to the local coordination committees.

A witness said a fire broke out in the mosque after security forces shot at it. "The whole neighborhood is echoing with the sound of bullets. Worshippers are running to take cover in alleyways," he said by telephone.

Another resident said: "Assad wants to finish off the uprising before international pressure becomes too much for him. But people have gone out of almost every major mosque in Deir Al-Zour, meters away from tanks that occupy every main square and roundabout."

Syrian state television said two members of the security forces were killed by gunmen in Douma, just outside Damascus.

Assad's forces have intensified assaults on towns and cities across the country since the start of Ramadan nearly two weeks ago to try to subdue mounting dissent against the ruling family, despite threats of new US sanctions and calls from Turkey and fellow Arab states to end attacks on civilians.

More than 1,700 civilians in all have been killed in the military crackdown on protests against Assad, activists say.

Syria says 500 soldiers and police have died in the upheaval, which it blames on armed gangs and terrorists.

US Secretary of State Hillary Clinton said on Friday Syria would be better off without Assad and called on nations that buy oil or sell arms to Syria to cut those ties.

"We urge those countries still buying Syrian oil or gas, those countries still sending Assad weapons, those countries whose political and economic support give him comfort in his brutality, to get on the right side of history," she said.

Syria's oil industry, with which the Assad has close links, generates most of the state's hard currency from crude output of 380,000 barrels per day.

While Syria exports crude oil, its refinery capacity is not sufficient to meet domestic demand for fuel. Trading sources said Swiss oil traders Vitol and Trafigura agreed to supply state firm Sytrol with 60,000 tons of gasoline this week.

The global campaign group Avaaz urged European nations on Friday to impose immediate restrictions on purchases of Syrian oil to "dry up" funding of Assad's security services. It said over 150,000 Avaaz members had signed a petition to that effect.

But there is little prospect of Western states putting teeth into the sanctions on Assad by targeting Syria's oil because of vested commercial interests against doing so.

Asked why the United States had not called on Assad to step down, Clinton said Washington had been "very clear" in its statements about Assad's loss of legitimacy, and wanted other nations to add their voices.