BANGALORE, India Eight small bombs exploded in quick succession across the south Indian city of Bangalore on Friday, killing a woman and wounding at least 15 people, 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. "Explosives have also been used, in quantity equal to one or two grenades."
Bangalore, known as India's Silicon Valley, is one of the world's most prominent centres 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.
India's home ministry said it suspected "a small militant group" was behind the attacks, but gave no details.
Several IT firms, as well as schools, colleges and cinemas, closed after news of the blasts broke. Phone lines were jammed.
"I was on my way to office when we heard a noise," witness Arun Daniel told the CNN-IBN TV channel. "It sounded like a cracker. The traffic was blocked, everyone was running around. It was not a severe blast."
Local TV showed a stall with broken windows and its concrete floor broken in pieces. Rubble littered another site. Sniffer dogs were used to trace clues.
One of the blasts occurred behind a bus stand, killing a woman, police said.
Bomb experts said gelatine sticks and a concoction of ammonium nitrate in fuel oil had been used to cause some of the explosions. Nuts, bolts and nails were also packed in the bombs.
"There were eight explosions of low intensity," Gopal Hosur, joint police commissioner for Bangalore, told Reuters. "At least one person was killed," he said. Police said one more person could have died.
India has suffered a wave of bombings in recent years, with targets ranging from mosques and Hindu temples to trains. It is unusual for any group to claim responsibility for attacks.
Islamist militant groups in Pakistan and Bangladesh intent on fanning hatred between Muslims and Hindus in India, and damaging a fragile peace process between New Delhi and Islamabad, are often blamed.
In May, eight bombs, many strapped to bicycles, ripped through a crowded shopping area in the western city of Jaipur, killing at least 63 people and injuring hundreds more.
Police said that attack bore some hallmarks of the Bangladeshi militant group Harkat-ul-Jihad al Islami (HuJI).
Bangalore also hosts vibrant biotechnology and aerospace industries as well as a garment sector employing more than 300,000 people.
Indian shares initially extended losses on Friday after reports of the blasts in Bangalore, but later recovered slightly.
The 30-share BSE index ended down around 3.4 percent, driven by rising oil prices and falls in regional markets amid concerns about the U.S. economy.