A suspected militant riding a motorcycle threw a hand grenade at participants in a pro-military rally in Quetta, the capital of Pakistan’s Balochistan province, on Wednesday, killing at least one person and injuring ten others, according to police and medical officials.

Local police chief Mohammad Malghani said the attack targeted a convoy of around 150 people traveling in cars and on motorcycles toward a hockey stadium to attend a government-organized event. The rally was held to celebrate recent retaliatory military strikes carried out by the Pakistani army inside Indian territory.

Waseem Baig, a spokesperson for the city’s Civil Hospital, confirmed that at least two of the injured are in critical condition.

No group immediately claimed responsibility for the attack, but suspicion is likely to fall on the Baloch Liberation Army, a separatist group that has waged an armed insurgency in the region for years and frequently targets Pakistani security forces and state symbols.