Turkish police shot dead two attackers and are searching for a third after a car bomb exploded outside a courthouse in the Aegean coastal city of Izmir, wounding at least 10 people, state media and local officials said.

The blast was caused by a car bomb, Izmir municipality secretary general Bugra Gokce told broadcaster CNN Turk.

A security source told Reuters police had shot dead two attackers following the blast, and the state-run Anadolu news agency said they were searching for a third. Hospital sources said ten people had been brought in wounded.

The bombing comes less than a week after a gunman shot dead 39 people at a nightclub in Istanbul on New Year's Day in an attack claimed by Islamic State. The gunman is still at large.

Turkey faces multiple security threats. It has been hit by a series of bombings over the past 18 months, some of them blamed on Islamic State, others on Kurdish militants.