A car bombing blamed on Kurdish militants rocked the Turkish city of Izmir on Thursday, killing at least two people and triggering a deadly shootout, as authorities chased the fugitive killer behind the New Year attack in Istanbul.

A car bomb killed 13 soldiers and wounded 56 when it ripped through a bus carrying off-duty military personnel in the central Turkish city of Kayseri on Saturday, an attack President Tayyip Erdogan blamed on Kurdish militants.

German police have arrested a 31-year-old Turkish man who is suspected of providing information on Kurds living in Germany to Turkish intelligence agencies, the German federal prosecutor's office announced on Friday.

An explosion killed two people and wounded more than a dozen outside the governor's office in the southern Turkish city of Adana on Thursday, weeks after the United States warned extremist groups were planning attacks.

A Turkish district governor wounded in a bomb attack on his office in the largely Kurdish southeast has died in hospital, the state-run Anadolu Agency and other media said on Friday.

Turkish police detained the editor and senior staff of a leading opposition newspaper on Monday over its alleged support for a failed coup in July, in a move described by a top EU politician as the crossing of a red line against freedom of expression.

The flow of Iranian natural gas to Turkey halted after an explosion hit a gas pipeline in eastern Turkey, a senior Iranian official told Iran's semi-official news agency Tasnim on Friday.

Nine Turkish soldiers were killed and more than 20 people were wounded on Sunday when suspected Kurdish militants detonated a car bomb that ripped through a checkpoint near a police station in the country's southeast, security sources said.

Two militants detonated explosives, killing themselves in a remote area near the Turkish capital, Ankara, on Saturday after police called on them to surrender, CNN Turk and other broadcasters reported.

Turkish police have captured a Kurdistan Workers Party (PKK) militant whom they suspect carried out a "motorbike bomb" attack on Thursday that wounded 10 people near an Istanbul police station, the state-run Anadolu Agency said on Friday.

Two members of the Turkish security forces were killed and eight others wounded on Monday in a roadside bombing by Kurdish militants in southeastern Turkey, local media reported.

Turkey will never allow the formation of an "artificial state" in northern Syria, Prime Minister Binali Yildirim said on Sunday, referring to the U.S.-backed Kurdish fighters whose advance Ankara is now aiming to stop.