MUMBAI - A four-storey building collapsed in India's financial capital of Mumbai on Tuesday, trapping dozens in the rubble, with at least four people confirmed dead, a fire department official said.

It was the second such collapse around Mumbai in less than ten days. Torrential rains that lash the city during the monsoon often destabilize older or badly constructed structures, leading to multiple building collapses over the years.

"We don't know exactly how many are trapped, but with the input provided by neighbours, we estimate more than 30 could be trapped," said the official, adding that rescue operations were hampered by narrow lanes in the area.

(Reporting by Nupur Anand and Rajendra Jadhav; Editing by Euan Rocha and Nick Macfie) ((Nupur.Anand@thomsonreuters.com;))