An investigation has been launched after an elderly woman was dragged along a London Underground platform and into a tunnel.

The 78-year-old woman suffered serious injuries after her bag became trapped between the doors of a train at Notting Hill Gate station, west London.

She was unable to free the bag or let go of it before the train departed despite being helped by others, accident investigators said.

Passengers who saw the woman in distress activated emergency alarms on the westbound Central line train and the driver applied the brakes.

Emergency services and London Underground’s emergency response unit rescued the woman from the space between the underside of the train and the tunnel wall.

She is still recovering in hospital following the incident at 4pm on January 31.

The Rail Accident Investigation Branch (RAIB) is seeking witnesses to help with its investigation, which aims to determine the sequence of events.

The process of checking whether it is safe for a train to depart and the door’s obstacle detection system will also be considered during the inquiry.

London Underground’s network operations director Nigel Holness said: “Our thoughts are with the woman injured in the incident at Notting Hill Gate. 

“The safety of our customers and staff is our top priority, and we will co-operate fully with the RAIB and implement any recommendations that come from their investigation or from our own internal investigation.”