MUMBAI - Indian police shot dead one man and arrested another in the financial hub of Mumbai on Tuesday, in what they said was a breakthrough in last month's train bombings that killed 186 people.

Indian police investigating the deadly Mumbai train blasts said they had arrested two brothers amid reports that one was a suspected senior commander of a top Muslim militant group.[AFP]

Acting on a tip-off, police surrounded a dilapidated building in the city centre and began searching for the two suspects linked with the attacks, a senior officer said.

The two were asked to surrender, but instead the men opened fired with automatic rifles, forcing police to return fire, he said. The incident took place at around 4:30 a.m. (2300 GMT).