In the first incident of its kind in the city, a low-intensity crude bomb exploded at the Odeon Deluxe theatre near RTC Crossroads in Chikkadpally here on Sunday night. A woman was seriously injured and three others received minor injuries. The explosion took place beside seat No. 25 in the �L� row on the second-floor balcony.

People rushed out immediately after hearing the explosion. There was a patch of blood by seat No. 10. Police suspects that two unidentified persons, aged between 35 and 40 years, had left a bag with explosives in the theatre. They were not seen after the explosion.

Odeon manager K.R.K Prasad said that the explosion took place at 10.20 pm. Their balcony seats 400 people, but there were only 180 people watching the film Lakshmi. The late show had started at 9 pm. People ran out of the theatre on hearing the explosion. The glass panes on the ground floor of the theatre were broken as the people tried to escape. Five people sustained minor injuries as they tried to escape.

However, film shows at Odeon Mini in the ground floor and the adjacent Odeon continued uninterrupted. Additional commissioner of police, Chikkadpally, B. Sumathi Reddy said that the injured had been admitted in a private hospital.Police said three persons had been picked up for questioning when they were moving near the theatre suspiciously.

The seriously injured woman was identified as Radhika who was shifted to the Gandhi hospital. �Somebody might have played mischief,� Ms Reddy said.A witness, Sandeep, told this correspondent that he saw a flash followed by a loud sound after which the viewers began rushing out. Commissioner of police A.K. Mohanty and a host of police officials rushed to the theatre.

The police pressed into service quick reaction teams, bomb detection and disposal squads, dog squads, forensics experts, and personnel whose expertise is to track down ISI fingerprints. In the past, explosions caused by improvised explosive devises had occurred at Madina Education Centre, the Railway Reservation Complex in Secunderabad, Sai Baba temple in Dilsukhnagar (in which four people were killed) and the police stations of Abids and Humayunagar in the city.