Syrian activists and Kurdish officials say fierce fighting is underway in a Syrian border town where Kurdish militiamen are struggling to repel advances by the Islamic State group.

The battle for Kobani is raging despite airstrikes by the U.S.-led coalition targeting the militants.

A Kurdish official, Ismet Sheikh Hasan, says Saturday's clashes are focused in the southern and eastern parts of the town. He says the situation is dire.

The director of the Britain-based Syrian Observatory for Human Rights, Rami Abdurrahman, says the town's Kurdish fighters are putting up a fierce fight but are outgunned by the militants

Since the militants launched their onslaught on Kobani in mid-September, at least 500 people have been killed and more than 200,000 have been forced to flee across the border into Turkey.