Iraqi Kurdish fighters have joined the fight against Islamic State militants in Kobani, hoping their support for fellow Kurds backed by U.S.-led airstrikes will keep the ultra-hardline group from seizing the Syrian border town.

The Syrian Observatory for Human Rights, which monitors the civil war, said heavy clashes erupted in Kobani and that both sides had suffered casualties, while the U.S. military said it had launched more air raids on Islamic State over the weekend.

Idriss Nassan, deputy minister for foreign affairs in Kobani district, said Iraqi Kurds using long-range artillery had joined the battle on Saturday night against Islamic State, which holds parts of Syria and Iraq as part of an ambition to redraw the map of the Middle East.