The driver of the tram which overturned in Croydon this morning, killing five people and injuring 51, has been arrested.
British Transport Police arrested the driver this afternoon but would not say what for and the cause of the crash remains unclear.
The tram derailed at around 6am and emergency services are still at the scene trying to free two people who remain trapped.
Prime Minister Theresa May offered her condolences to the victims.
She said: “My thoughts and prayers are with those who have been affected by the terrible incident on the tram in Croydon.
“The government is closely in touch with emergency services and other authorities to ensure that all is being done that is necessary to deal with this terrible incident.”
A British Transport Police spokesperson said: “We continue to work alongside our partners at the scene of a major incident in Croydon.
“We were called at 6.13am this morning after a tram derailed near Sandilands tram stop.
“At present, we can confirm five people have sadly died following this incident.
“More than 50 others have been taken to hospital with injuries.
“Officers are continuing to work at the scene and Rail Accident Investigation Bureau are investigating the cause of the derailment.
“One person has been arrested in connection with the incident and is currently in police custody.”
Deputy director of operations Peter McKenna, said: “We have treated a number of patients at the scene and took 51 patients to hospital.
“20 were taken to St George’s University Hospital and 31 to Croydon University Hospital.
“We remain on scene, supporting our emergency service colleagues as they deal with this incident.”
Anyone concerned about family and friends who may have been involved in the incident can call the Casualty Bureau on 0800 056 0154.