ANKARA,Turkey (AP) — Kurdish rebels on Wednesday claimed an attack at a police station in the mainly Kurdish city of Diyarbakir which authorities said was carried out with a ton of explosives planted inside a tunnel.
The blast occurred Tuesday at a workshop inside the police complex as an armored vehicle was being repaired. A police officer and two civilian employees were killed.
The Firat News agency, which is close to the rebels, said the Kurdistan Workers' Party, or PKK, claimed responsibility for the attack, which came as Turkey is heading toward a referendum on Sunday on whether to boost the president's powers.
At least five people were detained in connection with the attack, according to the Diyarbakir governor's office.
Interior Minister Suleyman Soylu had announced after the explosion that it appeared to be accidental, with no "outside intervention."
On Wednesday, however, he told Haber Turk television in an interview that investigators had concluded that it was an attack by assailants who had dug a tunnel and placed explosives beneath the vehicle repair facility.
The Diyarbakir governor's office said around a ton of explosives, including RDX, ammonium nitrate and TNT, were used. The tunnel was some 30 meters (98 feet) long, it said.
"Last night, it became clear that it was a terror attack," Soylu said.
The PKK has waged a three-decade old insurgency in southeast Turkey which has killed tens of thousands of people. The conflict reignited in 2015 after the collapse of a short-lived peace process.
The group is designated as a terror organization by Turkey and its allies.