A roadside bomb attached to a motorcycle went off near a police office in restive southwestern Pakistan on Saturday, killing at least two children and a woman and wounding 15 people, authorities said.

The bomb seemed to have been detonated remotely, and an investigation was ongoing, said police official Mujirbur Rehman. He said the wounded included police and passersby and some were hospitalized in critical condition in Quetta, the capital of Baluchistan province.

No one has immediately claimed responsibility for the attack in Pishin, a district in Balochistan. Suspicion is likely to fall on separatist groups that have stepped up attacks on security forces and civilians in recent months.

Interior Minister Mohsin Naqvi denounced the bombing in a statement and mourned the slain children, saying those behind the attack “do not deserve to be called humans.” He also vowed to continue the “war against terrorists and their facilitators until they are eliminated.”

For years, Baluchistan has been the scene of a low-level insurgency by groups demanding independence from the central government in Islamabad. Although the government says it has quelled the insurgency, violence in the province has persisted.