The police academy is home to about 600 students.
Three men in camouflage uniform covered their faces carrying Kalashnikovs stormed the building of Quetta Police Academy and started firing at the inmates of the dormitory.
At least 48 cadets and guards have been killed after the attack.
Hundreds of trainees were evacuated from Balochistan Police College as troops arrived to repel the militants.
Two of the militants died after detonating their bomb vests and one was killed by security forces, he said.
Many of the cadets were killed by the blasts, said Major General Sher Afgan of the Frontier Corps.
