The six-day-old assault on Hama, which has killed at least 100 people, seemed to do little to intimidate protesters, though the marches were smaller than previous Fridays, perhaps in part because this was the first Friday of the holy month of Ramadan, when Muslims fast from sunrise to sunset.
Protests spread from the capital, Damascus, to the southern province of Daraa and to Deir al-Zour in the east. Other demonstrations were reported in Homs in the center and in Qamishli, near the Turkish border.
"Hama, we are with you until death," a crowd marching through Damascus' central neighborhood of Midan shouted, clapping their hands as they chanted, "We don't want you Bashar" and "Bashar Leave," according to amateur videos from Friday posted on line by activists.
In another district of the capital, Qadam, protesters carried a banner reading, "Bashar is slaughtering the people and the international community is silent."
Security forces opened fire with live ammunition and tear gas in several cities, activists said. At least seven people were killed in the Damascus suburb of Arbeen, according to the London-based Observatory for Human Rights and the Local Coordination Committees, a group that tracks protests. They said one person was killed in the suburb of Moaddamiya and two in the central city of Homs.
State-run TV said reported that two policemen were killed and 8 wounded when they were ambushed in the northern town of Maarat al-Numan
Activists also said three people were wounded in Homs.
In Hama, government tanks shelled residential districts in Hama around 4 a.m., just as people were beginning their daily fast, one resident told The Associated Press.
The evening before, the shelling hit around sunset, while residents were having their meal breaking the fast, the resident said, asking for anonymity for fear of government reprisals.
"If people get wounded, it is almost impossible to take them to hospital," the resident said by telephone.
On previous Fridays - the day of the biggest protests - Hama has seen massive marches by hundreds of thousands that were the largest in Syria. But under the siege, with electricity, internet and phone services cut off and food supplies running short, there were no immediate reports of protests in the city during the day Friday.
Hama, a city of 800,000 with a history of dissent, had fallen largely out of government control since June as residents turned on the regime and blockaded the streets against encroaching tanks. But Syrian security forces backed by tanks and snipers launched a ferocious military offensive that left corpses in streets Sunday and sent residents fleeing for their lives, according to residents.
State-run Syrian TV on Friday showed footage from inside Hama, with images of streets blocked by makeshift barricades set up by protesters. It showed a tank removing a large cement barrier as well as a bus that had its windshield shattered.
The report also showed a yellow taxi car with a dead man in the driver's seat and bloodstains on the door. A picture carried by state-run news agency SANA showed empty streets with debris and damaged cars.
SANA said the Syrian army is restoring "security and stability" to Hama after it was "taken over by terrorists."
Hama has seen government crackdowns before. In 1982, Assad's father, Hafez Assad, ordered the military to quell a rebellion by Syrian members of the conservative Muslim Brotherhood movement there. Hama was sealed off and bombs dropped from above smashed swaths of the city and killed between 10,000 and 25,000 people, rights groups say.
Although there has been a near-total communications blackout in Hama, witnesses have painted a grim picture of life in the city.
"People are being slaughtered like sheep while walking in the street," a resident said Thursday, speaking by phone on condition of anonymity for fear of reprisals. "I saw with my own eyes one young boy on a motorcycle who was carrying vegetables being run over by a tank." He said he left Hama briefly through side roads to smuggle in food supplies.
The uprising began in mid-March, inspired by the revolutions sweeping the Arab world. Friday has become the main day for protests in Syria, despite the near-certainty that tanks and snipers will respond with deadly force.
More than 1,700 civilians have been killed in the regime crackdown on the uprising since March.
Assad has largely brushed off international pressure on his regime.
Russian President Dmitry Medvedev said Thursday he has warned Syria's leader that he will face a "sad fate" if he fails to introduce reforms in his country and open a peaceful dialogue with the opposition.
In the United States, the Obama administration moved to further isolate Assad and his inner circle imposing sanctions on a prominent pro-regime businessman and his firm.
Thursday's sanctions against Assad family confidante Muhammad Hamsho and his firm, Hamsho International Group, freeze any assets they may have in U.S. jurisdictions and bar Americans from doing business with them. Hamsho's holding company has about 20 subsidiaries ranging from construction, civil engineering, telecommunications and hotels to carpet sales, horse trading and ice cream production.