KABUL, Afghanistan (AP) — A bomb targeting a minibus in Afghanistan’s capital exploded Monday wounding at least 15 civilians, police said, amid a surge in attacks in Kabul.

Ferdaws Faramarz, spokesman for the Kabul police chief, said the minibus was attacked in the Dahan-e-Bagh area of Kabul and a taxi nearby was damaged.

He said the casualty count could rise.

The attack comes a day after separate bombings of vehicles in the western part of Kabul killed three people and wounded 12, Faramarz said.

He said the first explosion targeted a van and another vehicle was targeted in a different district. Faramarz said an investigation was ongoing but all the casualties were civilians.

No one immediately claimed responsibility for any of the attacks on Sunday and Monday. Afghanistan is experiencing a nationwide spike in bombings, targeted killings and other violence as peace negotiations in Qatar between the Taliban and the Afghan government continue.

The Islamic State group’s local affiliate has claimed responsibility for some of the violene, but many go unclaimed, with the government putting the blame on the Taliban. The insurgents have denied responsibility for most of the attacks.