Kurdish militants killed two Turkish soldiers in a roadside bombing on Sunday, the military said, apparently retaliating for Ankara's crackdown on the Kurdistan Workers Party (PKK) launched in tandem with strikes on Islamic State insurgents in Syria.
Long a reluctant member of the U.S.-led coalition against Islamic State, Turkey made a dramatic turnaround this week by granting the alliance access to its air bases and launching air raids against both the jihadist movement and the PKK.
But the relapse into serious conflict between Turkey and the PKK has raised doubts about the future of NATO member Turkey's peace process with Kurdish foes that started in 2012, after 28 years of bloodshed, but has recently stalled.
Military vehicle targeted
A car bomb and roadside explosives hit a passing military vehicle on a highway near Diyarbakir in the mainly Kurdish southeast of Turkey overnight on Sunday, an army said. Kurdish militants then opened fire on the vehicle with rifle fire, it said. Four other soldiers were wounded.
At least six people had been detained in connection with the attack, Dogan news agency reported.
The PKK, which Ankara and Washington deem a terrorist group, has also targeted police officers in the southeast and elsewhere, accusing the Islamist-rooted central government of covertly helping Islamic State to the detriment of Syrian Kurds.
The outlawed PKK has waged an insurgency against Ankara for Kurdish autonomy since 1984. Opposition politicians and critics accuse President Tayyip Erdogan of taking up the campaign against Islamic State as political cover to clamp down on Kurds.
Prime Minister Ahmet Davutoglu, who has said the operations will continue as long as Turkey faces a threat, discussed security with U.N. Secretary-General Ban Ki-moon in a telephone call overnight.
NATO said ambassadors will meet on Tuesday to discuss security at Turkey's request.
U.S. denies connection
A senior U.S. diplomat condemned recent PKK attacks but said there was no link between Turkey's new strikes on Kurdish militants and its newfound boldness in tackling Islamic State, which has seized large expanses of neighbouring Syria and Iraq.
