Air raids by the Syrian air force on rebel positions in Syria's Latakia city have killed 20 militants.The air force on Saturday carried out a series of airstrikes on the positions of the al-Qaeda-linked Nusra front in Latakia, Xinhua reported citing the state news agency SANA.Meanwhile, the Syrian Observatory for Human Rights, a Britain-based watchdog group said several jihadi groups fired grad missiles into government troops' positions in the town of Qardaha, the hometown of President Bashar al-Assad.Battles in the countryside of Latakia have been raging amid heavy government troops' shelling on the rebels positions to keep them from advancing toward Latakia.The Nusra front and like-minded groups who have taken large chunks of the province of Idlib are threatening that they will keep advancing toward Latakia, as it is close to the western countryside of Idlib.