Damascus: Syrian troops continued their crackdown in the north of the country, with more civilian deaths reported, as the United States accused Iran of backing the assault on pro-democracy protesters.

Activists said security forces were continuing to sweep through villages near the flashpoint northeastern town of Jisr al-Shughur, which troops captured on Sunday.

"Six civilians perished in the past few hours in Ariha," east of Jisr al-Shughur, an activist told AFP in Nicosia, without providing further details.

The deaths came after fresh protests erupted in the eastern town of Deir Ezzor, a rights activist said.

Protesters have described the operation in the northern mountains as a scorched-earth campaign, while Syrian soldiers who deserted to Turkey have alleged they were forced to commit atrocities there.

Forces stationed in the town shot dead a family of four in Jisr al-Shughur on Monday, London-based rights activist Rami Abdel Rahman said.

According to a toll released on Tuesday by the Syrian Observatory for Human Rights, the violence has claimed the lives of 1,297 civilians and 340 security force members in
Syria since the unrest erupted mid-March.

Washington meanwhile accused Iran of backing Syria's assaults on pro-democracy protesters and again urged Assad to end the violence.

"Iran is supporting the Assad regime's vicious assaults on peaceful protesters and military actions against its own cities," Secretary of State Hillary Clinton said.

She compared its response to the Islamic republic's 2009 crackdown on its own pro-reform protests.

"President Assad needs to engage in political dialogue," White House spokesman Jay Carney said earlier.

"A transition needs to take place. If President Assad does not lead that transition then he should step aside."

Turkish Prime Minister Recep Tayyip Erdogan telephoned Syria's President Assad on Tuesday, urging him to "refrain from violence and end the unrest", Anatolia news agency reported.