Syrian rebels have clashed with government troops after converging on a military airport in Aleppo, a monitoring group and state media said, as the United States said it was considering "all possible options" to help the opposition. Buoyed by victory in the strategic town of Qusayr on the border with Lebanon, President Bashar al-Assad's troops have been readying to open a northern front in Aleppo province on the border with Turkey.

Syrian rebels on Sunday opened fire on two Iraqi border posts along the southern edge of the two countries' frontier, killing one guard and wounding two others, officials said. Iraqi border guards Colonel Nayif Zaili said Syrian rebels fired on two posts which lay two kilometres (1.25 miles) from the Al-Waleed border crossing linking the two countries. One Iraqi border guard was killed and two others were wounded, he said. A doctor at a nearby hospital confirmed the toll.

Syrian helicopters fired rockets near a Lebanese border area whose residents back the rebellion against President Bashar al-Assad, a security official said, in the latest incident rasing new concerns of Syria-related escalation in Lebanon. The late Friday raid was second such Syrian strike against the Sunni-majority border areas in less than a week. "Syrian helicopters fired rockets at the Wadi Hmeid area near (the town of ) Arsal. There were no casualties," the Lebanese official said on condition of anonymity.

MOSCOW (Reuters) - Russia, a fierce opponent of foreign military intervention in Syria, voiced concern on Thursday that unnamed powers might use allegations of chemical weapons attacks to justify such action. "The issue of chemical weapons has become the subject of speculation and provocation," Foreign Minister Sergei Lavrov told a news conference with his German and Finnish counterparts. "I do not rule out that somebody wants to use it to state that a red line has been crossed and a foreign intervention is necessary," he said.