At least six soldiers were killed Tuesday in an attack by unidentified militants on a military checkpoint south of the Libyan city of Sirte. Two army vehicles were burnt in the attack at dawn which was carried out in the town of Khuchum al-Kheil, some 120 km south of Sirte, an army officer in charge of the checkpoint was quoted by the Libya News Agency as saying. The area was cordoned off by the forces and search for the culprits is underway, the official added. Owing to the lack of military and police forces, Libya is struggling to restore security and social order by relying on pro- government militia since former ruler Muammar Gaddafi was toppled in October 2011.