Kolkata: Two people, including a woman, were killed and seven others injured in an explosion that took place in a multi-storey building at Metiabruz area here on Sunday night, police said.

The bombs exploded around 9 pm in the ground floor of a three-storied building of Masjidtala locality when at least 15 embroidery workers were on work there, according to the police report.

Rajia Khatun and Shamir Khan, both 30-year-old, died on the spot while the rest sustained critical burnt injuries. The injured were shifted to the state-run SSKM Hospital.

The condition of some of the injured was stated to be serious, sources said.

Senior police officers including a bomb and dog squad are at the spot. The cause of the explosion is yet to be ascertained.

The entire area was cordoned off and no arrest made.