At least 18 people are reported to have died in clashes in Syria as opposition activists called a general strike. 11 of the deaths were in the cities of Homs and Hama, the opposition Local Co-ordination Committees (LCC) said. Two people also died in clashes between troops and deserters in the northern Idlib province, the Syrian Observatory for Human Rights reported. Authorities in Idlib confronted members of \"an armed terrorist group\", said Syrian state news agency SANA. The UN estimates more than 4,000 people have died in the nine-month uprising, including 307 children. Syria severely restricts access to foreign media so reports of unrest cannot be verified. The LCC said the casualties it had recorded on Sunday included two children. There were also reports of clashes between defectors and troops in the south, near the border with Jordan. In Jordan itself, protests at the Syrian embassy in the capital Amman turned violent for the first time. The embassy said protesters stormed the building and attacked staff, but the brother of one of the protesters told the BBC that they were assaulted when they went into the embassy wearing opposition flags. Heavy machine-gun fire was heard and two armoured carriers were burned in pre-dawn clashes in Kfar Takharim town in Idlib province, the British-based Syrian Observatory of Human Rights said. Reuters news agency quoted residents and activists as saying army defectors had also clashed with loyalist forces backed by tanks in the town of Busra al-Harir, not far from the border with Jordan. The Observatory said that a general strike called by opposition activists was being \"very widely observed\" in southern Syria\'s Daraa province on Sunday, the start of the working week. And schoolchildren and civil servants stayed at home in some parts of Damascus, although central districts opened as normal, the activist group said. Fear of pro-government militias prevented some shopkeepers from joining the strike, one Damascus resident told the BBC. Shopkeepers who kept the shutters down in Idlib province had their property burned by troops who issued a warning via loudspeakers from a nearby mosque, the LCC said. The LCC also said the strike was being well observed by students at Aleppo University and by residents of the town of Douma near Damascus, where it said casualties had been reported. Syrian President Bashar al-Assad is under international pressure to end the continuing crackdown on anti-government protesters. The Arab League is reported to be holding two emergency meetings in the coming days, to discuss Damascus\'s response to the League\'s plan to send in monitors. Last month the League suspended Syria\'s membership in protest at the continuing crackdown and also imposed economic sanctions.