Gulf Arab states on Saturday turned up the heat on Damascus, joining a growing chorus of pressure after Syrian security forces shot dead at least 22 people as tens of thousands staged anti-regime protests.

The six-member Gulf Cooperation Council called for an "immediate end to violence... and bloodshed."

The State Department on Friday urged Americans in Syria to leave the country immediately and advised those who remain in the country to restrict their movements, as the Syrian government intensified a violent crackdown on opposition protesters.

The warning came as congressional calls grew for the Obama administration to impose severe new sanctions on President Bashar Assad's regime.

The military prosecutor general has charged two Lebanese men with allegedly smuggling weapons from the Beirut Marina to Syria, a security source told As Safir daily published Saturday.

Wasim Tamim and Samir Tamim, who hail from the northern port city of Tripoli, are members of the most prominent movements in the former parliamentary majority, sources said in reference to ex-PM Saad Hariri’s al-Mustaqbal movement.

Activists said Saturday that at least 24 Syrian civilians have been killed as security forces fired on anti-government protesters as part of a nationwide crackdown.

Syria-based rights activist Mustafa Osso said most of the deaths occurred in Damascus suburbs during daytime Friday protests and late night demonstrations following evening Ramadan prayers.

Thousands of people demonstrated in the northern port city of Tripoli on Friday night to protest Syrian President Bashar Assad’s deadly crackdown on pro-freedom protestors.

The demonstrators marched at around 11:00 pm in several Tripoli neighborhoods after holding a sit-in at the city’s al-Tall square. They returned to the square and held prayers for the soul of thousands of people killed by the regime in Syria.

The U.S., French and German leaders pledged to consider new steps to punish Syria after security forces shot dead at least 24 people as tens of thousands staged anti-regime protests on the first Friday of Ramadan.

President Barack Obama spoke separately to France's Nicolas Sarkozy and German Chancellor Angela Merkel as Western nations cranked up pressure on Syrian leader Bashar al-Assad.

Turkey said Friday the Syrian regime's deadly crackdown on civilian protestors is "unacceptable" and "illegitimate", Anatolia news agency reported.

"The developments in Syria as I emphasized before are unacceptable," Anatolia quoted Foreign Minister Ahmet Davutoglu as saying.

Syria’s banned Muslim Brotherhood on Friday lashed out at Prime Minister Najib Miqati, accusing him of “siding with the killers of Syrian children.”

In a statement published by the Italian news agency AKI, the Brotherhood’s official spokesman Zuheir Salem said “the Syrian people would never compromise, no matter the sacrifices, the blood of our brothers in Lebanon, whether in Tripoli, Beirut, Sidon … or anywhere in Lebanon.”

Prominent Syrian liberal poet and writer Adonis urged Syrian President Bashar Assad to step down, but called on the opposition to adopt a strict secular ideology, in comments published Friday.

"President Assad should do something. If I were in his place, I would leave the presidency," Adonis said in an interview with Kuwait's al-Rai newspaper.

The Gulf state of Kuwait on Friday urged a halt in Syria's deadly crackdown on pro-democracy protesters and called for dialogue and "true reforms" to end the crisis.

"The state of Kuwait expresses its extreme pain for the continued bloodshed among the brotherly Syrian people," said a statement by a foreign ministry official cited by state news agency KUNA.