A remote-controlled bomb explosion on Thursday killed four members of tribal peace force (Lashkar) in a Pakistani tribal agency, bordering Afghanistan, said sources. The explosion took place in Tirah Valley of Khyber tribal agency. Tribal Administration sources told KUNA that the Lashkar members were taking a round of the area when their jeep hit a roadside bomb. The blast killed four Lashkar memebrs and wounded three others, said sources. They added that the wounded were said to be in critical condition.