ANKARA: Kurdish rebels raided a Turkish police station and fired on railway workers in two separate attacks that left five dead, officials said Friday, amid renewed conflict between the security forces and insurgents that has wrecked a fragile peace process.

Violence has sharply increased in Turkey in the past week, with the government launching aerial strikes against Kurdistan Workers’ Party, or PKK, bases in northern Iraq, and the rebels escalating attacks against Turkey’s security forces. Some 20 people, most of them soldiers, have died in the renewed violence.

PKK militants raided the police station in the town of Pozanti, in southern Adana province, late on Thursday, killing two policemen and touching off a gunfight that also killed two rebels, said Gov. Mustafa Buyuk. He said the rebels were armed with automatic rifles and hand grenades.

In the eastern province of Kars, the rebels detonated a bomb they placed on rail tracks and later fired on rail workers who were sent to repair the line, the region’s deputy governor, Adem Unal, told the state-run Anadolu Agency. One of the workers was killed.