Syrian forces shot dead 16 people on Friday when they fired on protesters demanding the removal of President Bashar al-Assad, activists said, and European powers said Damascus should face tougher sanctions for the violence.

Tens of thousands of people rallied across the country, defying Assad's military crackdown and ignoring a pledge that his tycoon cousin Rami Makhlouf, a symbol of corruption, would renounce his business empire and channel his wealth to charity.

The worst bloodshed was in Homs, where activists said eight protesters were killed and state television said a policeman was killed by gunmen. One person was also reported killed in the northern commercial hub of Aleppo, the first protester to die there since unrest erupted in the south of the country in March.

Friday Muslim prayers have provided a platform for the biggest protests in the three-month uprising, inspired by revolts which have overthrown the leaders of Egypt and Tunisia and challenged autocrats across the Arab world.

Activists said tens of thousands of people protested in the southern province of Deraa where the revolt against Assad's rule began, as well as in the Kurdish east, the city of Hama north of Damascus, and suburbs of the capital itself.

Two northern towns were also encircled by army units, residents said, five days after the military retook the rebellious town of Jisr al-Shughour and sent thousands of refugees streaming across the nearby border into Turkey.

Syrian rights groups say 1,300 civilians and more than 300 soldiers and police have been killed since the protests broke out in March against 41 years of rule by the Assad family, and 10,000 people have been detained.

Authorities blame the violence on armed groups and Islamists, backed by foreign powers. Syria has barred most international journalists, making it difficult to verify accounts from activists and officials.

Assad has responded to the unrest with a mix of military repression and political gestures aimed at addressing protesters' grievances.

On Thursday state media said Makhlouf was quitting business and handing proceeds to charity. Makhlouf controls a string of businesses including Syria's largest mobile phone operator, duty free shops, an oil concession, an airline company and hotel, construction concerns, and shares in at least one bank.

He has been subject to U.S. sanctions since 2007 for what Washington calls public corruption, as well as EU sanctions imposed in May, but repeatedly maintained that he was a legitimate businessman whose firms employ thousands of Syrians.

Activists said Makhlouf's step by itself would not curb the momentum of protests. They said Assad, who has only spoken twice in public since the uprising started, was expected to address the country soon and might unveil further measures.

Assad faces international condemnation over the violence, and has seen the first signs of cracks in his security forces after a clash in Jisr al-Shughour earlier this month in which the government said 120 security personnel were killed.

There have been no mass desertions from the military, but analysts say it is unclear how long the loyalty of rank and file Sunni Muslim conscripts will last if the crackdown on mainly Sunni protesters continues.

Assad's family and many military commanders are members of the Alawite sect, an offshoot of Shi'ite Islam.

French President Nicolas Sarkozy said on Friday that France and Germany had agreed to lobby for stronger sanctions against Syria for "unacceptable actions and repression" of protesters.

Damascus is already subject to targeted U.S. and European Union sanctions against its leadership, and EU nations have been preparing a fresh round of sanctions aimed at companies and banks, according to European diplomats.

But France has been unable to rally support at the U.N. Security Council for a resolution condemning Assad's crackdown, in part because of reluctance from veto-holding council members China and Russia.

"I believe there is a realization that force is being used against the people in a way that is not acceptable," German Chancellor Angela Merkel said after talks with Sarkozy. "Therefore both of us will talk to Russia in our own ways to (ensure) we are successful."

Germany's Foreign Minister Guido Westerwelle spoke to his Brazilian counterpart Celso Amorim, urging a clear response by the Security Council to the violence in Syria, German Foreign Ministry sources said.

A witness in the Damascus suburb of Irbin said protesters burned a Russian flag to protest against Moscow's stance.

Syrian forces have surrounded two towns on the main north-south road linking Damascus with Aleppo. Villagers have been streaming out of the towns, fearful of an assault similar to the one witnessed in Jisr al-Shughour.

The state news agency has said army units deployed near Khan Sheikhoun and Maarat al-Numaan to ensure the highway's safety.

Turkish Foreign Minister Ahmet Davutoglu held talks with a Syrian envoy on Thursday in which he called on Damascus to end the violent crackdown and pass democratic reforms.

Turkish officials said the number of refugees who had crossed over from Syria had reached 9,600, and another 10,000 were sheltering by the border just inside Syria.

In the northern Lebanese city of Tripoli two people were killed in a clash between Sunni and Alawite residents, a military source said, after an anti-Assad demonstration erupted following noon prayers.

The source said one of those killed was an off-duty soldier caught in the crossfire and the other person was a civilian. Four people were wounded but it was not clear from which side.