Description:Syrian rebels say they have seized a convoy of United Nations observers near the Golan Heights, according to videos posted on the internet on Wednesday. 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.(0:47)