The Piccadilly line has been suspended after a woman was hit by a train in north London.
British Transport Police, London Fire Brigade and London Ambulance Service crews rushed to Arsenal Underground Station to reports of a casualty on the tracks shortly after 9am on Friday.
A woman, in her 20s, was taken to hospital following the incident, a BTP spokeswoman said.
Her injuries are not believed to be serious.
Shocked commuters were forced to evacuate the station.
One person wrote on Twitter: “Evacuated from Arsenal station …someone on the tracks. Lots of people crying outside – seems quite bad.”
Another person added: “Something pretty serious going down at #arsenalstation ambulances, fire engines, police everywhere.”
A statement posted on Transport for London’s website said there was no service on the Piccadilly line between Kings Cross and Cockfosters due to a person on the track.
The station reopened shortly before 10.30am with severe delays expected until 11.15am.