Dozens of people were injured in the crush and people did what they could to try and escape (Picture: ABPLive)

A rush hour stampede at a railway station in the Indian financial hub of Mumbai killed at least 21 people and wounded more than 20, a hospital official said.

The cause of the stampede at the Elphinstone railway station amid a heavy downpour was being investigated, said a police official at the site of the accident.

People were huddling under the canopy covering the bridge to escape heavy rains, making the deadly tragedy worse, said lawmaker Shaina Nana Chudasama of the governing Bhartiya Janata Party.

Earlier Police said the stampede was triggered by a rumour that a pedestrian overpass collapsed after concrete chunks fell. Chaos prevailed as people surged forward to leave the bridge.

Paramedics have taken the injured to a hospital, the police control room said.

People were crushed against barriers on a staircase leading to a bridge over railway lines