A 24-year-old youth was shot at and critically injured at Saidpur hostel in Bahadur police station area on Monday, a day after violent clashes between two groups of Patna University students.

Shivam Kumar (24) of Mahnar in Vaishali district was alone in a room of hostel number 1, where he resided illegally, when he was shot at around 6.15pm. He was admitted to a private nursing home in Raja Bazar in a serious condition.

Nobody saw the attackers as power supply to the area was disconnected at the time of the attack, a hostel inmate told the police. Patna City sub-divisional police officer Rajesh Kumar said hostel inmates fled after the incident. 'Efforts are on to ascertain the identity of those involved in the murderous attack,' he said.

Residents said tension was brewing at the university's hotels for three days over collection of chanda (donation) for Saraswati Puja.

Before Monday's attack, Patna City superintendent of police (SP) Shivdeep Lande had served Pirbahore police station house officer (SHO) Nishar Ahmed a 24-hour deadline to remove unauthorised occupants from Patna University's hostels. 'I have threatened the SHO with stern action if the order is not complied with,' he said.

Earlier, on Sunday evening, two crude bombs were hurled and a few rounds fired in the air when Saidpur and Jackson hostels inmates clashed. Unconfirmed reports said two students suffered splinter injuries and were being treated.

SHO Ahmed said the police could not initiate action against the unauthorised inmates for want of reinforcements from district police lines.

Sources said the force from police lines failed to report to Pirbahore because the sergeant major was ill. 'The force will probably be dispatched on Tuesday,' an officer at district police lines said.

Patna College principal Nawal Kishore Choudhary washed his hands of the matter, saying he has already written to the police station asking them to evict unauthorised occupants. Illegal inmates were evicted from Jackson, Minto and Saidpur hostels two months ago. However, a month back, some illegal inmates re-entered. 'Sunday's incident was the fallout of differences between two groups over organising Saraswati Puja on the campus,' a source said.

Regarding Sunday's clash, Pirbahore SHO Ahmed said four persons have been named as accused in the FIR. A witness identified three people.

Acting Patna SSP Vinay Kumar said patrolling has been intensified.