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

Warplanes pounded 17 targets in the province of Hakkari on Monday and Tuesday, 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. Critics accuse President Tayyip Erdogan of attempting to use the violence to win back nationalist support after a stinging election setback for the ruling AK Party in June.

“Our fight will continue until not one terrorist is left within our borders and until concrete is poured over (their weapons),” Erdogan said at a military ceremony on Tuesday. 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 have 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.

The military later confirmed its forces had come under attack in Sirnak and had launched air strikes to take out two PKK heavy machine gun positions. One PKK militant was also killed in a clash in Bingol province, the local governor’s office said.

The United States and the European Union, like Turkey, classify the PKK as a terrorist organisation. Moreover, Two prosecutors behind a graft probe that targeted the inner circle of Turkish President Recep Tayyip Erdogan fled to Armenia via Georgia after an arrest warrant was issued against them, officials said Friday. The Istanbul prosecutor’s office on Monday ordered the arrest of Zekeriya Oz, Celal Kara and Mehmet Yuzgec on accusations of “forming an organisation to commit crime” and “attempting to overthrow the government by force”.

But police found out that Oz and Kara had fled to Georgia early Monday just 10 minutes apart, the official Anatolia news agency said, indicating they had found out about the warrant before it was formally issued. From there, the pair crossed into the neighbouring Armenia, said Kemal Girit, the governor of the Black Sea province of Artvin on the Georgian border.

Turkey has no diplomatic relations with Armenia after they are frozen due to the dispute over the massacres from 1915 of Armenians in the Ottoman Empire, which Yerevan regards as genocide, a term Ankara vehemently rejects. Anatolia released CCTV footage purporting to show the prosecutors carrying their suitcases as they left Turkish territory via the Sarp border post. The two apparently had to take the route because the border between Turkey and Armenia has long been closed. Hurriyet newspaper had earlier said that Ankara contacted Georgian authorities to seek their extradition. Turkish police were still hunting for Yuzgec, it added.

The three prosecutors had been disqualified from their functions in May for allegedly abusing their authority by leading the December 2013 graft probe that rocked then-prime minister Erdogan’s government, claiming four of his ministers. The corruption case was later dropped due to a “lack of evidence”. Erdogan, who came out fighting from the crisis and won the presidency in August last year, claimed the investigation was an attempted “judicial coup” staged by US-based Muslim cleric Fethullah Gulen and his followers in Turkish state administrations.

The president has promised no mercy in the fight against Gulen, and authorities have effectively purged the police force and judiciary of thousands of alleged pro-Gulenist elements, arresting people considered close to the preacher. Erdogan’s Islamic-rooted Justice and Development Party (AKP) failed to win an overall majority in June legislative elections for the first time since coming to power in 2002, plunging Turkey into political uncertainty.