Qatar has indefinitely closed its embassy in Damascus after pro-Assad demonstrators attacked the building housing it, the quasi-official Syrian newspaper Al-Watan reported Monday.
"Members of the Qatari diplomatic mission have informed us that work in the embassy is suspended," a Syrian employee at the embassy told the paper.
"They have also informed us that all diplomats of the embassy and its consular affairs section will leave for Qatar," he added.
There was no immediate official confirmation from either country.
Last week, government supporters threw stones, eggs and tomatoes at the Qatari embassy in protest against the Doha-based satellite news network Al Jazeera's coverage of the unrest in the country. No casualties were reported.
The incident follows last week's attacks on the US and French embassies by Assad loyalists, but no immediate reason for the attack has been offered.
Meanwhile, At least 30 people were killed in overnight clashes between opposition protesters and Assad gunmen in the central Syrian city of Homs.
"More than 30 civilians have been killed over the past 24 hours in Homs in clashes that broke out late on Saturday between the opposition and supporters of the regime," Rami Abdul Rahman of the London-based Syrian Observatory for Human Rights told reporters.
Rahman said the clashes came after three regime supporters kidnapped last week were killed and their dismembered bodies were returned to their relatives on Saturday.
"These clashes are a dangerous development that undermines the revolution and serves the interests of its enemies who want it to turn into a civil war," he added.
"This infighting represents a serious shift and could be a sign of a coming civil war," it added.
Videos posted on YouTube by protesters in Homs show what they say are bodies of protesters burnt to death by Assad gunmen.
Warning: Graphic Depictions of the Dead
Also Sunday night, supporters of Assad, who is facing unprecedented protests, held a massive rally in Damascus to mark the 11th anniversary of his rule.
The event featured a concert as part of what the official Syrian press agency SANA termed the "Festival of Gratitude to the Nation".
The Interior Ministry said on Monday it would use all "forms of firmness" against opposition demonstrations, who it branded terror groups of masked gunmen staging an armed insurrection.
Syria has been gripped by pro-democracy protests since mid-March in which more than 1,400 people have been killed, according to human rights groups.