Passengers at two Tube stations were injured - one severely - when they were dragged along platforms after their coats got stuck in train doors.

An independent investigation by the Government's Rail Accident Investigation Branch (RAIB) will seek to determine what happened during the incidents in Archway and Chalk Farm underground stations this year.

A statement on the RAIB website said that at around 3.50pm on February 18, a passenger’s coat became trapped in the doors of a northbound Northern line train at Archway station.

As the train departed, the passenger was dragged for approximately two metres until their coat became free from the door.

The passenger and their companion both fell to the ground during the accident, with the passenger sustaining a serious injury.

The train stopped after it had travelled for about 20m.

At around 11pm on April 20, a passenger’s coat became trapped in the doors of a southbound Northern line train at Chalk Farm station.

This passenger was dragged for just under 20m, again until their coat became free of the doors.

The passenger fell onto the platform during the accident and sustained minor injuries.

The train did not stop and continued on its journey.

The website statement says the investigation will identify the sequences of events which led to the accidents.

Officers will also look at the actions of those involved and anything that may have influenced them, as well as the arrangements to manage and control the risks associated with passengers boarding and alighting from Underground trains.

The management of train platform accidents after the incidents and any underlying management factors will also be considered.

The findings, including any recommendations to improve safety, will be available on the goverment website.