The city police commissioner told reporters that four officers and a security guard were among the wounded. The guard's injuries were serious.
"It appears that some explosives may have been hidden in the wall" next to a gate leading to the stadium, said Shankar Bidari, whose comments were broadcast on several news channels. "The explosives weren't powerful."
Initial investigations show that the explosives used in the blasts were locally made and of low intensity, M.R. Poojar, a deputy police commissioner told The Associated Press.
Earlier police and local cricket officials had said the explosion was the result of an electricity generator blowing up.
The sound of the blasts, which took place as thousands of spectators were entering the stadium, sent nervous crowds running in panic.
The game started to a packed stadium an hour behind schedule. Poojar said security around the stadium had been increased.
Bangalore is set to host some of next year's cricket World Cup matches. The International Cricket Council said it was too early to comment on the attack.
Sports venues in India have faced tight security amid fears that Islamist radical groups may target them.
Neighboring Pakistan, which sees near-daily bombings from militants, has been off limits to foreign cricket teams since gunmen attacked the Sri Lanka team's bus in Lahore last year, killing six police officers and the van's driver.
The Pakistan Cricket Board was forced to organize its home series in the United Arab Emirates. Meanwhile, Pakistan's home test series against New Zealand last year was played on opposition soil and this year's against Australia took place in England.
