QUETTA: A mysterious blast inside a seminary rocked Quetta, the capital of Balochistan on Sunday morning.

The powerful blast left two people injured and destroyed five mud-walled rooms inside the madrassah (religious school) in eastern bypass area of Quetta.

Superintendent of Police Sariab, Bashir Ahmed Brahvi told Dawn.com that the seminary was being used by terrorists to carry out subversive activities in the city, already plagued by attacks of Baloch separatists and violent sectarian attacks.

"Afghans were preparing explosive materials inside the seminary," Brahvi said without naming any faction of the Afghan Taliban.

The strength of the blast was heard far and wide causing panic in the city. According to bomb disposal squad, the blast was caused by 20 kilogram explosive material.

"The site of the explosion is colored with blood," Brahvi said, adding that the two injured had not approached any hospital for treatment. The injured individuals disappeared soon after the blast.

Brahvi said police recovered huge quantity of explosives, acid, detonators and literature in foreign languages from the madrassah.

"The madrassah had no sign board and it was not registered," he explained.

Another police official who requested anonymity owing to the sensitivity of the matter told Dawn.com that the blast has caused casualties. "The terrorists managed to shift the dead bodies and injured before the arrival of police," he said.

"You can see blood and destruction everywhere," he added. Police and personnel of secret services reached the seminary and launched an investigation into the incident. No arrest was made. There has also been no claim of responsibility for the blast.

In another incident, militants hurled a hand-held bomb at a house in Hazara Town area of Quetta. Police said the blast partially damaged the house and smashed the glasses of nearby homes. There were no fatalities as a result of the blast in the area.