At least 14 people have been killed after Syrian security forces opened fire on protesters.

Rights groups and activists say the deaths occurred Friday in areas including the capital, Damascus, the southern city of Daraa and the northern Idlib region. There are also reports of security forces using tear gas on demonstrators.

Tens of thousands of Syrians rallied across the country, despite the government's ongoing crackdown on dissent.

Activists had urged citizens to protest against the imprisonment of hundreds of people in the government's crackdown on pro-democracy protesters.

The call to protest comes a day after Syrian rights activists said government forces had killed six people and arrested more than 20 others across the nation since Wednesday.

There was no independent confirmation of the casualties. Syria does not allow foreign media into flashpoint areas.

Syrian President Bashar al-Assad has been trying to crush a four-month old opposition uprising against his 11-year autocratic rule.

He also has made promises of political reforms, but opposition groups have dismissed the offers and demanded an end to the deadly crackdown on their movement.