The massive manhunt for the perpetrators of the suspected terror attack on the Indian Institute of Science campus in Bangalore has been intensified and a high-level meeting on Thursday will take stock of the security situation in the city.

Wednesday's daring strike has unnerved the country's technology hub that houses some of the top software firms, which have now been asked to tighten security.

Special teams have been formed, and a vigorous combing operation is on, police sources said.

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Chief Minister N Dharam Singh has convened an emergency meeting top home department and police officials to review the security in the city, which is also home to organisations like Bharat Electronics [Get Quote] Limited and Indian Space Research Organisation.

Eyewitnesses said a lone gunman entered the campus and started firing indiscriminately on delegates who were coming out of the J N Tata Auditorium, venue of an international conference on Operations Research Applications.

M C Puri, a retired professor from IIT, Delhi, succumbed to bullet injuries.

An AK-47 rifle, three magazines, 11 spent cartridges and an unexploded hand-grenade were recovered from the scene.

Sources at the M S Ramaiah Memorial Hospital and Mallige Hospital where four injured, including Prof. Vijay Chandru, part of the team that developed hand-held computer 'Simputer', were rushed said those injured are out of danger.

Chandru, involved in the team that developed the hand-held Linux based computer, received severe bullet wounds is progressing.

The severed blood arteries had been reconnected and blood supply restored successfully, Dr Sriram, who attended on him, said. His left shoulder bone had been damaged and he might require another surgery, he added.

The terror attack came on a day when extradited gangster Abu Salem [Images] was brought to the city for polygraph, brain-mapping and narco-analysis tests at the Forensic Science Laboratory.