Turkey's military killed 18 Islamic State militants in northern Syria over the last 24 hours, intensifying strikes against the militant group.<br/><br/>Army today said, 4 buildings and one vehicle used by the Islamic State fighters were destroyed in the strikes. Separately, five Turkey-backed rebels and five Islamic State militants were killed in clashes on the ground. <br/><br/>Turkey is backing a group of Syrian Arabs and Turkmen in northern Syria in its Euphrates Shield operation, which has swept Islamic State from its southern border.