Saudi Arabia urged its citizens on Tuesday to quickly leave Syria to avoid getting caught in a military crackdown on months of popular protests, the Saudi state news agency reported.

"The foreign ministry renewed its warning to citizens currently in Syria to leave swiftly and asked those planning trips there not to travel now due to the unrest witnessed by the Syrian arena," the agency said.

The appeal came two days after the Arab League decided to impose sanctions on the government of President Bashar Assad over its refusal to allow monitors to enter the country to monitor rights abuses.

Saudi Arabia has taken a leading role among Arab states in condemning Assad's use of troops and tanks to crush street unrest. In August King Abdullah urged Syria to end bloodshed and recalled his country's ambassador from Damascus.

Saudi Arabia said earlier this month that one of its citizens had been killed by Syrian government forces in the restive city of Homs.

The crackdown has become one of the most violent episodes in the wave of unrest sweeping through the Arab world this year. Assad's government says it is fighting criminals and armed extremists who have provoked violence by attacking its troops.

Human rights activists and Western countries say Assad's forces have attacked peaceful protesters.