BEIRUT - Islamic State fighters attacked a military airport in Syria's Homs province on Monday as they pushed on with an offensive against government strongholds towards the west, a monitoring group said.
Skirmishes by Islamic State -- which is strongest in the northeast and east -- into the provinces of Hama, Homs and even Damascus pose a fresh challenge for Syrian President Bashar Assad.
Syria's army has carved a bulwark of territory from Damascus through the cities of Homs and Hama to the western coast by defeating other, less powerful militias including rebels fighting under the banner of the Free Syrian Army.
The Syrian Observatory for Human Rights, which tracks the violence through a network of sources in the country, said Islamic State attacked a military airport in Tadmur, a town in Homs province, early on Monday.
Syrian officials could not immediately be reached for comment, and the fighting was not reported on state media.
The offensive followed a three-day battle erupted on Friday further west in Hama around Sheikh Hilal village, the Observatory said. Islamic State was trying to cut the road from Hama to Aleppo, once Syria's most populous city, it added.