Eight Turkish police officers were wounded on Friday when a bomb exploded in a roadside vehicle as their minibus passed on a highway in the southeastern province of Diyarbakir, security sources said.

Interior Minister Suleyman Soylu said two people had been detained and were believed to be the perpetrators of the blast.

“There was an explosion in a parked vehicle at 5:10 am as a police vehicle was going to work in Diyarbakir,” he said.

The Diyarbakir governor’s office said the bomb had not critically hurt anyone, but nine people who had been in the armoured minibus had been taken to hospital for checkups.

The blast occurred near a livestock market some 6 miles south of the centre of Diyarbakir, the largest city in the region, the sources said.

There was no immediate claim of responsibility. Kurdish, leftist, and Islamist militants have all carried out bomb attacks in Turkey in the past.

A bomb killed six people and wounded dozens in Turkey’s largest city, Istanbul, last month. Dozens of people, including a Syrian woman, were detained as suspects.

Turkey blamed Kurdish militants for that blast, but no group claimed responsibility then, either. The Kurdistan Workers Party (PKK) and Kurdish-led Syrian Democratic Forces (SDF) denied involvement.

The PKK launched an insurgency against the Turkish state in 1984, largely focused in Turkey’s mainly Kurdish southeast. More than 40,000 people have been killed in the conflict.

It is considered a terrorist organization by Turkey, the European Union, and the United States.