Three Syrian officers were killed when their helicopter was downed by Islamic State (IS) militants in the northern province of Aleppo, a monitor group reported on Saturday.The helicopter was downed by the IS overnight in the vicinity of the Kwers airbase, which is besieged by the IS militants in the eastern countryside of Aleppo, said the Syrian Observatory for Human Rights (SOHR).Separately, the London-based watchdog group said the militant groups targeted government troops' positions in the districts of Ashrafiyeh and Khalidiyeh in northern Aleppo, adding that the Syrian forces fired two surface-to-surface missiles on the rebel-held district of Bani Zaid, with no reports on losses yet.In the central province of Hama, SOHR said the rebels launched a "violent attack" against government troops' checkpoints in northern Hama, adding that the Syrian air force carried out 13 air strikes on the rebel-held town of Latamneh in northern Hama.
Also on Saturday, intense clashes continued between the IS militants and fighters of the Kurdish People's Protection Units (YPG) in the northern countryside of the northern province of al-Raqqa, the de facto capital of the IS, Xinhua news agency reported.The YPG fighters succeeded in completing their siege of the town of Suluk and are inching toward the predominantly Kurdish city of Tal Abyad near the Turkish border.The Kurdish fighters have recently been engaged in intense battles with the IS militants in the hope of recapturing predominantly Kurdish towns in northern Syria.SOHR said the air strikes by the US-led anti-terror coalition are backing the Kurdish fighters in their push to reach Tal Abyad.