The Turkish military ratcheted up pressure on Kurdish militants with a fresh round of air strikes in the southeast of the country yesterday as the rebels claimed responsibility for the bombing of a police station in Istanbul.

Warplanes pounded 17 targets in the province of Hakkari on Monday and yesterday, the military said, part of a renewed crackdown on the outlawed Kurdistan Workers Party (PKK) which has waged a three-decade insurgency for Kurdish autonomy.

Nato member Turkey started what it called a “synchronised war on terror” last month, attacking PKK fighters in northern Iraq and, less frequently, Islamic State militants in northern Syria.

By largely focusing on the PKK – both in neighbouring Iraq and at home – Ankara has raised suspicions among Kurds that its real agenda is to check Kurdish territorial ambitions rather than to crush the hardline Islamists.

The Kurds have retaliated with violence. Yesterday, the PKK claimed responsibility for Monday’s bombing of the police station in which four people died, three of them attackers.

The bombing was one of a wave of attacks on Turkish security forces that killed at least nine people.

In a statement published online, the PKK named the three of its militants who died in the attack and the subsequent firefight. It also called for a focus on attacks that “damage the enemy” rather than just sacrificing the fighter.

The air strikes in Hakkari followed operations on Sunday in the eastern Agri province, which killed seven PKK militants, according to the local governor’s office.

In ground fighting, security sources said the PKK attacked a military station in Sirnak, a province adjacent to Hakkari, and killed one soldier in a 20-minute battle.

One PKK militant was also killed in a clash in Bingol province, the local governor’s office said.