DIYARBAKIR, Turkey (Reuters) – Turkish troops have killed 16 Kurdish guerrillas in an operation in south-east Turkey targeting militants who launched a bomb attack on a military convoy that killed five soldiers, the local governor’s office said on Thursday.

The clashes are part of a growing cycle of violence in the remote, mountainous province of Hakkari bordering Iraq and Iran – a development which Turkish officials and analysts are linking to the deepening conflict in Syria.

The army sent in troop reinforcements and helicopter gunships after Kurdistan Workers Party (PKK) rebels detonated remote-controlled bombs in the convoy attack in Hakkari’s Semdinli district on Wednesday.

Five soldiers were killed and seven wounded in that attack, the Hakkari governor’s office said in a statement. It said operations against the militants were continuing.

More than 40,000 people have been killed in the conflict between the PKK and Turkish forces since the militants launched their insurgency 28 years ago with the aim of carving out a separate state in mainly Kurdish south-east Turkey.

The conflict is focused in the mountainous region bordering Iraq and Iran, but the PKK has also carried out attacks in Turkish cities. Officials blamed it for a car bombing on Monday which killed nine people in the city of Gaziantep, near Turkey’s south-eastern border with Syria.

The PKK, listed as a terrorist organization by Turkey, the United States and the European Union, has denied involvement in that attack.

Prime Minister Tayyip Erdogan has accused Syrian President Bashar al-Assad of backing PKK fighters and has warned of military intervention in Syria if the group uses Syrian territory to threaten Turkey.