Turkish police have shot dead a suspected attacker in the western Aegean city of Izmir after an explosion outside a courthouse on Thursday, a security source said.

At least three people were wounded in the suspected car bomb near a courthouse, a correspondent for the Dogan news agency at the scene told broadcaster CNN Turk.

The correspondent said he saw the three people being put on stretchers by rescue workers.

A large number of judges and lawyers were at the entrance to the courthouse at the time.

İzmir adliye patlama çatışma sesleri varmış pic.twitter.com/EpuKU3iIYM — Aykut Kaya (@aykutcky) January 5, 2017

Photos emerging on social media show a car on fire in the courthouse carpark.

Emergency services attended the scene and police evacuated the area, believing there may be a second blast planned.

It follows a series of terror attacks across Turkey by extremist groups.

Isis claimed responsibility for the latest attack in the early hours of New Year's Day, where a gunman massacred 39 people at a nightclub in Istanbul.

Izmir is the third most populous city in Turkey, after Istanbul and Ankara.

It is a popular city for tourists with easy access to the country's coastline.

Reuters