QUETTA, Pakistan — Gunmen have taken over parts of a hospital in southwestern Pakistan Saturday after two bomb blasts in the city, including one that went off inside the hospital’s emergency room, killed at least 12 people, according to officials.

Armed men captured different sections of the hospital complex and were positioned on rooftops, said the head of police operations in Quetta, Fayaz Sumbal.

Frontier Corps troops and police commandos have been called in, and security officials were trying to clear the hospital as quickly as possible, Sumbal said.

An Associated Press reporter on the scene could hear intermittent gunfire as troops took up positions around the building.

The violence in Baluchistan, a vast province in southwestern Pakistan, started when a blast ripped through a bus carrying female university students.

At least 11 people died in the incident, and another 19 were wounded, said police chief Mir Zubair Mahmood.

As family, friends and rescuers crowded the emergency room where the dead and wounded were taken, another blast went off in the corridor.

A top government official was killed in the blast and two other people wounded, said Sumbal.