Seven small bombs exploded in quick succession across the south Indian IT city of Bangalore Friday, killing two people and wounding at least 15, police said. “In all these cases they have created the blast using timer devices,” Bangalore Commissioner of Police Shankar Bidari told reporters at the site of one of the blasts. M.R. Pujar, additional police commissioner for Bangalore, said “crude explosives” had been used. One woman was killed in an explosion at a bus stop in the city's Madiwala neighborhood while another person died later of his injuries, police said. There was no immediate claim of responsibility. Intelligence sources said it was too early to say who may have been behind Friday's attacks. “We are looking at the pattern of the explosions, and are trying to work out who is behind them and why,” a federal Intelligence Bureau official said. But The Times of India quoted an Intelligence Bureau source as saying that the SIMI and LeT may be behind the serial blasts. The SIMI and LeT operatives have been arrested and they are being interrogated. Bangalore, known as India's Silicon Valley, is one of the world's most prominent centers for software development and is also the capital of its outsourcing industry. Also nicknamed the “world's back office”, it is home to more than 1,500 top firms, including India's Infosys Technologies and Wipro and offices of global firms such as Microsoft Corp and Intel Corp.