Police recovered five live bombs and explosive materials at Patna University's Saidpur Hostel during a raid late on Saturday night.

Senior superintendent of police Manu Maharaaj claimed the explosives had been stored allegedly for carrying out some sort of campus violence.

Two BN College students - Bajrangi Kumar and Mukesh Kumar - suffered injuries while trying to escape during the raid. While the police claimed they had tried to jump off the roof, students protesting the police action at Kargil Chowk said they had been pushed off the hostel's top floor. The students were rushed to Patna Medical College and Hospital from where they were shifted to a private hospital.

Maharaaj said the raid - that began around 10pm continued till 5 on Sunday morning - following intelligence inputs that illegal explosives had been stored to attack a group of students allegedly involved in an assault on a student belonging to the rival faction a couple of days ago.

Officers from Kadamkuan, Sultanganj, Bahadurpur and Agamkuan police stations were assigned the task to conduct the raid at hostels number 1 and 2. Four students, including Abhishek, Ashutosh and Bhagwat, were taken into custody.

Maharaaj said the five live bombs and a large quantity of bomb-making materials were seized during the raid.

Some illegal boarders tried to thwart the police operation but had to retreat as the security personnel outnumbered them.

"They were making bombs at the time of the raid," Maharaaj said, adding that had the police not searched the hostel, the illegal boarders would have carried out a major incident. "Timely intervention of the police foiled a major incident in Patna."

Saidpur Hostel had been in the news in December 2011 when the police recovered the body of postgraduate student Dilip Kumar from an abandoned cafeteria on the premises. Last year, a 24-year-old youth was shot at and critically injured.

The hostel had been made encroachment-free last September on the directive of Patna High Court. It had taken the district administration and Patna University more than eight years to evict the illegal occupants from the Saidpur campus, but encroachers returned soon enough.

On Sunday morning, students gathered near Kargil Chowk to protest the students' arrest and alleged high-handedness of the police. "The police thrashed the students after ascertaining their caste," a student leader told The Telegraph.

Police sources said Mukesh suffered injuries on his shoulder and hands, while Bajrangi fractured his right foot.

Patna University registrar Sanjay Kumar Sinha said the university was unaware about the police action against the borders at Saidpur hostel. "No permission had been sought from us to conduct such a raid," he said.