DAMASCUS, July 21, 2018 (MENA) - Twenty-six people have been killed and others injured in a Russian-Syrian air shelling that targeted sites held by Daesh terrorist group in Daraa province, Syrian sources said on Saturday. The number of the killings is expected to rise, as the injured are in critical condition, Alhurra News channel reported, quoting sources as saying. Daesh militants are still holding more than 40,000 civilian hostages to push the governmental forces to stop attacking the area, according to the sources. On Friday, 28 Daesh militants and Syrian army forces were killed in clashes and shelling in the eastern outskirts of Daraa and Deir-Ezzor, local sources said. Meanwhile, several explosions were heard in the vicinity of Khmeimim Air Base in Latakia countryside, where Russian forces are stationed, according to the Syrian Observatory for Human Rights. The cause of the explosions was found to be a drone strike, that Russian forces managed to drop.