A fifth raid southwest of Kobane destroyed an IS armed vehicle and a sixth strike decimated an artillery cannon on the "southern edge" of the town, it said.
Despite the airstrikes, IS fighters managed to push into parts of the town, located on the Syria-Turkish border, also known under its Arabic name of Ain Al-Arab. An activist group said the strikes killed at least 45 fighters since late Monday, forcing them to withdraw from parts of Kobane.
The Britain-based Syrian Observatory for Human Rights said Wednesday's strikes targeted IS fighters east of Kobane and them to withdraw from several streets they had controlled earlier. Meanwhile, an attack apparently carried out by Kurdish fighters inside the town destroyed a mosque minaret, which IS group had used as an outlook, activists said.
Heavy gunfire was heard from inside the town in a sign of fresh clashes on Wednesday. The Observatory said most of the fighting as in the town's Kani Arban neighborhood.
Kobane has been under the onslaught of the IS group since mid-September when IS fighters launched their offensive in the area, capturing several Kurdish villages around the town and bringing Syria's civil war yet again to Turkey's doorstep.
The fighting has forced some 200,000 of the town residents and villagers from the area to flee and seek shelter across the frontier in Turkey. Activists also say that more than 400 people have been killed in the fighting.
IS has conquered vast swaths of Syria and Iraq, declaring a self-styled caliphate governed by its strict interpretation of Islamic teaching, or Shariah.