Russian President Vladimir Putin said on Tuesday it was important to avoid actions that might aggravate Syria's civil war, a veiled warning against foreign military intervention or arming anti-government forces.
Israeli jets devastated Syrian targets near Damascus on Sunday in a heavy overnight air raid that Western and Israeli officials called a new strike on Iranian missiles bound for Lebanon's Hezbollah.
The White House said on Friday it was continuing to study evidence that the Syrian government has used chemical weapons and would not set a timetable for corroborating reports.
The U.S. intelligence community believes Syria used chemical weapons on anti-government rebels.
Syrian forces have used chemical weapons against rebel forces and civilians, the head of Israel's military research said.
Syrian rebels have overrun several towns near the Israeli-occupied Golan Heights in the past 24 hours, rebels and a monitoring group said on Thursday, fuelling tensions in the sensitive military zone.
U.N. peacekeepers monitoring the ceasefire line between Syria and the Israeli-occupied Golan Heights have scaled back patrols after rebels detained 21 Filipino observers for three days last week, diplomats said on Thursday.
Syrian rebels say they have seized a convoy of United Nations observers near the Golan Heights, according to videos posted on the Internet site YouTube on Wednesday by a violence monitoring group.A young man saying he was from the "Martyrs of Yarmouk" brigade said the convoy would not be released until forces loyal to President Bashar al-Assad withdrew from the village of Jamla, a mile east of the ceasefire line with the Israeli-occupied Golan.
Croatia will pull its soldiers out of the U.N. peace force in the Golan Heights as a precautionary step, the government said on Thursday, after media reports that Croatian arms were being sent to Syrian rebels fighting President Bashar al-Assad.