Protesters in Hama took to the streets for the 17th consecutive Friday to demand an end to Assad's rule [Reuters]
Syrian forces have killed at least six civilians during shelling in the eastern city of Deir ez-Zor, as government forces intensified a pre-Ramadan crackdown against protests, activists said.
Deir ez-Zor, the capital of a province that carries the same name, is an oil hub but also one of the country's poorest regions.
"More tank columns are heading to town. By using heavy weapons, security forces are waging war against their own people," the Syrian Revolution Co-ordination Union grassroots activists' group said late on Saturday.
Activists have predicted that demonstrations will escalate during the Islamic holy month of Ramadan, which begins on Monday, as both sides try to tip the balance in the more than four-month uprising.
Syria-based rights activist Mustafa Osso said the regime had detained more than 4,000 people in raids over the past week as it tries to contain the situation.
"The regime is trying to suppress the uprising because it knows that the opposition will try to hold protests between sunset and sunrise," Osso said.
He called the week of raids the "strongest security campaign since the uprising began".
On Saturday, government forces stormed parts of the eastern city of Deir ez-Zor and barraged neighbourhoods with heavy machine-gun fire, two days after army defectors fought with Assad loyalists, activists said.
Rami Abdul-Rahman, the director of the London-based Syrian Observatory for Human Rights, said about 60 vehicles filled with reinforcements from the northern city of Raqqah reached Deir ez-Zor after noon.
"Intense shooting could be heard in the western parts of the city," he told The Associated Press news agency by telephone.
"Residents have placed barriers in the streets in order to obstruct advancing troops."
The tribal region, which borders Iraq, has been witnessing intense protests, calling for the downfall of Assad's regime.
Authorities have waged a brutal crackdown nationwide that activists say has killed more than 1,600 civilians since the protests against the regime began in mid-March.
The government has sought to discredit those behind the protests by saying they are terrorists and foreign extremists, rather than true reform-seekers.
Since the uprising against Assad's regime began, Fridays have witnessed the most intense protests as Muslims leave mosques after the weekly prayers and march in the streets.
The Deir ez-Zor raid followed a night-time attack by government forces on the capital, Damascus, and the eastern city of al-Boukamal on the border with Iraq.
Last week, Assad fired and replaced the governor of Deir ez-Zor after massive anti-government demonstrations in the area.
Activists said Samir al-Sheik, who was a Damascus-based police brigadier general, was chosen to
try to put an end to protests in the region.
They also said scores of people also were detained elsewhere in Syria on Saturday, most in the eastern town of al-Boukamal, the northern province of Idlib and some Damascus suburbs.
Also on Saturday, Lebanese security officials said Syrian troops had opened fire at about 50 families fleeing the crackdown into northern Lebanon.
The officials, who spoke on condition of anonymity in line with regulations, said no one was hurt and the families entered the Lebanese village of Knayseh.