QUETTA, Pakistan (AP) — An explosive device carried on a motorcycle by two suspected militants in restive southwestern Pakistan ignited prematurely near a police station Monday killing the suspects, police said.

The blast happened in Killa Abdullah, a town 75 kilometers (45 miles) north of Quetta, the provincial capital of Balochistan. Local police officer Ghulam Rasool said the men were near the Mezai police station when the blast took place.

He said officers were still investigating to determine whether either of the suspects was a suicide bomber targeting the police station. Rasool provided no further details.

Balochistan for decades has been the scene of a low-level insurgency by small separatists groups demanding independence from the federal government and a greater share in the region’s natural resources, such as gas and oil. Militants from the Pakistani Taliban and the Islamic State group are also active in the province.

Last month, a suicide bomber dispatched by the outlawed Balochistan Liberation Army blew himself up at a train station in Quetta, killing 26 people, including soldiers and railway staff, in one of the deadly recent attacks.