TBILISI (AFP) - Four Georgian soldiers have been killed in Afghanistan, the defence ministry said Friday, in the biggest loss for the ex-Soviet republics military since it deployed in the war-torn country. It was unclear whether the Georgians were among six international soldiers that NATO announced Thursday had been killed in Taliban attacks. The ministry said in a statement that the four soldiers were killed by an explosive device and that Georgia was working to bring their bodies home as soon as possible. The dead included a colonel, a sergeant and two corporals, it said. Defence ministry spokesman Levan Papaskiri told AFP the soldiers had been killed on Thursday but refused to provide any other details. Georgia suffered its first loss in Afghanistan last month when a soldier was killed in a bomb attack. Meanwhile, two Romanian soldiers were killed Friday in a landmine explosion in Afghanistan, the Ministry of Defence said in Bucharest. A third Romanian soldier was injured by the blast and taken to the military hospital of Lagman base. The incident occurred in the southern province of Zabul. Meanwhile, NATO said an airstrike left 15 militants dead in the countrys northeast near the Pakistan border. NATO said it called in airstrikes in the northeastern province of Kunar on the Pakistani border, killing 15 insurgents setting up what has been known as a historical attack position. Afghan leaders have criticised airstrikes on the grounds that they can result in collateral damage, but NATO said Friday no civilians were killed. ISAF claimed its troops killed up to 114 insurgents in September - exactly twice the number of ISAF troops who died in the same time period. It also claimed to have captured or killed more than 105 Haqqani network and Taliban leaders, including shadow governors and weapons facilitators. The statement could not be independently verified.