Car bomb attack kills four police in Turkey's Diyarbakir -official

A car bomb attack killed four Turkish police officers and wounded 20 other people in the southeastern city of Diyarbakir on Thursday, a government official said, the latest violence to hit the biggest city in the largely Kurdish region.

The attack targeted a minibus carrying members of the police special forces, a security source said, adding that civilians were also among the wounded. The explosion hit the vehicle as it passed near a bus station in Diyarbakir, broadcaster Haberturk TV said. Ambulances rushed to the scene, it said.

The southeast has been scorched by waves of violence since a ceasefire between the outlawed Kurdistan Workers Party (PKK) and the government collapsed last July.

There was no immediate claim of responsibility for the attack. A PKK offshoot has claimed two car bomb attacks this year in the capital Ankara.

The first, on February 17, targeted a military bus and killed 29 people, most of them soldiers. The second, just under a month later, tore through a crowded transport hub and killed 37 people.

NATO member Turkey faces multiple security threats. As part of a U.S.-led coalition, it is fighting Islamic State in neighbouring Syria and Iraq. In the southeast, the collapse of the 2-1/2-year ceasefire has meanwhile triggered some of the worst violence since the 1990s.

In Istanbul this month a suicide bomber, who the government said was a member of Islamic State, killed three Israeli tourists and an Iranian.