QUETTA, Sept 21: Seven seminary students who were injured in a blast on Friday disappeared on Saturday from the Civil Hospital where they were under treatment, apparently to avoid arrest and interrogation.

“The injured students admitted to the surgical ward left the hospital without informing the medical staff,” hospital sources said.

They said disappearance was noticed when police officials came to the hospital to record their statement about the explosion which killed six people and injured a dozen of others.“We are questioning all students and teachers of the madressah to find facts about the blast,” Capital City Police Officer Mohammad Akbar told Dawn, adding that the nature of the blast shows that it was not a simple grenade attack.

“Such a powerful explosion cannot be caused by a grenade,” he said.

He said initial investigations revealed that destruction in the seminary was the result of a huge blast which occurred inside a room. “We expect to resolve the mystery of the blast soon,” he said.

The madressah administration said that some people had hurled an explosive device while some other students informed police that two men had come to the madressah and left after Juma prayers. The blast took place in the afternoon.

Sources said that police were looking for the students who had fled from the hospital. Now a police party had been deployed in the hospital to keep an eye on other people injured in the blast.Four out of the six people killed in the blast have been buried near the madressah.

The madressah was established in 2006 and around 50 students were studying there.

It is located in a deserted area some 30 kilometres west of Quetta.