The latest deaths came after fresh protests erupted in the eastern town of Deir Ezzor, a human rights activist said and troops pursued a scorched earth campaign in northern mountains, sending thousands fleeing.
“The armed forces are continuing their operations and the sweep of the villages near Jisr al-Shughur,” the flashpoint northeastern town which the army took by force on Sunday, the activist said.
“Six civilians perished in the past few hours in Ariha,” east of Jisr al-Shughur, he said, without providing further details.
“Some 10 tanks and 15-20 troop carriers were deployed around the town of Abu Kamal,” 500 kilometres east of Damascus near the border with Iraq, the activist added.
The United States stepped up its condemnation of the crackdown, which rights activists say has left at least 1,200 people dead since mid-March, and again called on its president to allow for a political transition or step aside.
“We have called on President Bashar al-Assad to cease the violence. We strongly condemn, in the strongest possible terms, the violence being perpetrated in Syria,” said White House spokesman Jay Carney.
“President Assad needs to engage in political dialogue. A transition needs to take place. If President Assad does not lead that transition then he should step aside,” he said.
Refugees fleeing across the border into Turkey said troops were burning crops and slaughtering livestock in villages near Jisr al-Shughur, main focus of a crackdown which began at the weekend.
Those claims could not be confirmed, as Syria has prevented journalists from entering the area.
“What happened there over the weekend and what continues to occur is absolutely revolting, and we condemn these barbaric acts in the strongest possible terms,” State Department spokesman Mark Toner said.
Toner insisted the United States was exerting pressure on the Syrian government but stopped short of calling on Assad to resign.
European powers stepped up their campaigning meanwhile for a draft resolution condemning the crackdown, with one top envoy saying the delay in Security Council action has cost hundreds of lives.
Russia and China strongly oppose UN action against Assad and could veto any resolution.
The Europeans believe if they can get a strong enough majority in favour it would increase pressure on Russia and China not to use their veto right.
The United Nations said more than 10,000 Syrians have fled into neighbouring countries to escape the crackdown.
There are 5,000 people in Lebanon, said UN humanitarian affairs spokeswoman Stephanie Bunker. A Turkish official said Tuesday there are now more than 8,500 Syrians who have crossed into Turkey.
UN emergency relief coordinator Valerie Amos made a new appeal to the Syrian government to let a UN humanitarian team make a proper assessment.
Syria has refused to let UN aid experts visit stricken towns and blocked rights investigators from entering the country.
Refugees arriving in Turkey said fighting had also broken out among Syrian troops on Sunday as soldiers bent on destroying the area were confronted by others trying to defend the townsfolk.
Elements from one tank division had even taken up positions by bridges leading into the town in a bid to defend it, they said.
