Militants set off a powerful car bomb outside the headquarters of Pakistan’s paramilitary security forces in the southwestern city of Quetta on Tuesday, killing at least ten people and wounding dozens, authorities said.

Axar.az reports, citing AP, before detonating their vehicle, four attackers who were inside the car stepped outside and engaged the troops in an intense shootout, according to the police.

Residents said the blast was so powerful it was heard from miles away. Ambulances rushed to the site in front of the Frontier Constabulary and rescuers transported the wounded to nearby hospitals.

No group immediately claimed responsibility, though suspicion is likely to fall on separatist groups that often target civilians and security forces in insurgency-plagued Balochistan, where Quetta is the provincial capital.

According to provincial health minister Bakhat Kakar there were concerns the death toll could rise further.