BEIRUT (AP) — Activists say the U.S.-led coalition has struck targets of the Islamic State group near a besieged Kurdish town along Syria's border with Turkey.

It was not immediately clear if Tuesday's airstrikes succeeded in halting the militants' advance on Koubani, also known as Ayn Arab.

The Britain-based Syrian Observatory for Human Rights said the strikes hit Islamic State fighters east and west of Kobani. The Local Coordination Committees, another activist group, also confirmed the airstrikes on the town's outskirts.

Koubani has been under attack by the Islamic State group since mid-September. Despite U.S.-led airstrikes, the militants were able to advance toward the town over the past few days.

The Observatory says fighting around Koubani on Monday killed 57 fighters on both sides — the town's Kurdish defenders and the Islamic militants.