BEIRUT (Reuters) -Two people were killed in Lebanon on Wednesday in an exchange of fire between Hezbollah members and residents of a Christian village after a truck belonging to the heavily armed Shi'ite group overturned in the area, security sources said. A member of the Iran-backed Hezbollah and a resident of the mountain village of Kahaleh were killed in the clash, some 12 km (7 miles) southeast of Beirut, the sources said. It marked the most serious confrontation between Hezbollah and its Le