BEIRUT (Reuters) -- Gunmen shot the mayor of a town in Lebanon and killed two of his companions only hours after he oversaw a hostage swap with a rival clan in an area increasingly riven by sectarian divisions, security sources said on Sunday.
The attack near the border with Syria highlights how the civil war there has worsened enmity between Lebanese Shi'ite and Sunni Muslim militias that support opposing sides of the two-year-old conflict.
Mayor Ali Hujeiri, a Sunni from the town of Arsal, was shot in the majority Shi'ite town of Labweh as he returned from the hostage exchange with a rival Shi'ite clan. The sources said the attack was carried out by residents of the area, but did not elaborate.
The Bekaa Valley region, where the attack happened, is religiously mixed. Some areas are controlled by the Shi'ite militant Hezbollah group, which is helping President Bashar al-Assad crush the revolt. Other parts, like Arsal, are Sunni, and residents provide a safe haven for majority-Sunni Syrian rebels.
The hostages were being held in relation to an incident in June in which four of Labweh's residents were killed by rebel fighters, the sources said.
The recapture of the Syrian border town of Qusair in June by Mr Assad's forces, spearheaded by Hezbollah guerrillas, led to an influx of Syrian rebel fighters and civilians into Lebanon and more violence spilling over into the Bekaa region.
Rockets fired from areas believed to be controlled by Syrian rebels have targeted the Shi'ite town of Hermel, while Syrian helicopters have crossed into Lebanon and fired at buildings in Arsal.