BEIRUT - Syrian rebels kidnapped 13 Lebanese Shi'ites in the northern province of Aleppo on Tuesday as they returned home from a pilgrimage, triggering protests in Beirut in the latest unrest to spill over from Syria's 14-month-old uprising.The abductions follow street fighting in the Lebanese capital sparked by the killing of a Lebanese Sunni Muslim cleric opposed to Syrian President Bashar Assad - the worst clashes in Beirut since 2008 sectarian fighting that brought back memories of Lebanon's 15-year civil war."When we crossed the border around 40 gunmen stopped the bus and forced it into a nearby orchard and said women should stay on the bus and men get out," Hayat Awali, who identified herself as a passenger, told Lebanon's Al Jadeed TV from Aleppo."We told them we are only pilgrims. They said 'take your pilgrims and go the police station in Aleppo and tell them we have prisoners there and we want them'."A member of one of the disparate bands of insurgents who fight under the umbrella of the FSA, contacted by the Internet telephone channel Skype in Aleppo, denied any personal knowledge of the abduction.Hezbollah leader Hassan Nasrallah appealed for restraint in an address broadcast by Lebanese TV stations, saying: "...any act of violence or individual action will not help this case at all".The abductions came hours after a court released on bail a Sunni Muslim whose arrest earlier this month sparked unrest in a Sunni region of north Lebanon that backs the revolt against Assad, a member of the minority Alawite sect.The kidnappings also underscored how far Syria is from finding a way out of the chaos and bloodshed that has marked the uprising against Assad, which a UN peace plan hopes to resolve through talks based on a ceasefire that has yet to take hold.Families of the kidnapped men blocked roads including the airport highway in the Shi'ite Muslim southern suburbs of Beirut - a stronghold of the Hezbollah political movement and guerrillas who are Syria's allies - to demand their release."The Free Syrian Army (FSA) said they took them. They let women go and kept the men. They told them that they will keep them until the Syrian army releases FSA detainees," a relative of one of the men said.