At least three people have been killed as Syrian security forces launched raids in two regions of the country.
Activists and witnesses say armored vehicles rolled into the coastal city of Latakia on Saturday, a day after thousands of anti-government protesters rallied in the city. They say security forces killed two people and left others wounded.
A separate raid took place in the Qusair region, near the Lebanese border, where activists say at least one person was killed.
Saturday's unrest comes a day after security forces killed at least 19 people across the country. Activists and witnesses say most of the deaths occurred after demonstrators took to the streets and renewed calls for President Bashar al-Assad's resignation.
President Assad has been facing growing international condemnation for his crackdown on dissent.
On Saturday, U.S. President Barack Obama and Saudi Arabia's King Abdullah called for an immediate end to the crackdown. A U.S. White House statement says the leaders agreed that the Syrian government's "brutal campaign of violence" against civilians should stop immediately.
In a separate phone call, Mr. Obama and British Prime Minister David Cameron also agreed on the need for an "immediate" end to the bloodshed.
Canada announced Saturday, it is expanding its economic sanctions against Syria.
U.S. officials have estimated that more than 2,000 people have been killed in the months-long effort to suppress dissent in the country.
Also Saturday, one of the world's largest Muslim inter-governmental organizations urged Syria to exercise restraint. The Organization of Islamic Cooperation also offered to play a role in dialogue in Syria.
The United Nations Security Council plans to meet on Thursday to consider further action against the Syrian government. Earlier this month, the Security Council issued a statement condemning Syria for attacks on civilians and widespread human rights violations.
The Syrian government has blamed armed groups for much of the country's violence. On Saturday, state media reports said funerals were held for three security officers who were killed by "armed terrorists" near Damascus and the central city of Homs.
Details of events in Syria are difficult to independently verify because the government allows very few foreign news reporters into the country and restricts their movements.
Some information for this report was provided by AP, AFP and Reuters.