Renewed calls for Syrian President Bashar al-Assad's resignation have been met with a deadly response from the country's security forces.

Activists and witnesses say at least eight people were killed on Friday as government forces cracked down on dissent.

They say at least one death occurred in Hama, a flashpoint city that was under a military siege for more than a week. On Wednesday, the government said the army had pulled out of the city after “restoring stability.” Rights groups and activists said more than 100 people were killed during the siege.

Deaths were also reported after protests got underway in the Damascus region and in the central city of Homs on Friday.

Earlier Friday, government forces began carrying out raids in anticipation of the protests. Rights groups and activists say a woman was killed after tanks and soldiers launched an assault in Khan Sheikhon in the northern province of Idlib. Also, a man was shot and killed after fleeing forces in the Damascus suburb of Saqba.

Thousands of anti-government protesters massed in streets across Syria despite the government crackdown, which has been drawing growing international condemnation.

On Thursday, in an interview with CBS News, U.S. Secretary of State Hillary Clinton called on Europe and China to impose additional sanctions on Syria's oil and gas industry.

When asked why the United States has not yet called for Syria's president to step down, Secretary Clinton said it was important that the American voice is not the only one calling for Mr. Assad's removal.

Also Thursday, U.S. President Barack Obama and Turkish Prime Minister Recep Tayyip Erdogan spoke by phone and agreed on the need for a transition to democracy and an immediate end to the bloodshed in Syria.

Details of events in Syria are difficult to confirm because the government allows very few foreign news reporters into the country and restricts their movements.