An internal investigation will be launched after a British Transport Police (BTP) car was in collision with another car on the tramlines outside East Croydon station last night.

The car was on its way to Norbury station, to help colleagues who had been challenged by a group of youths, when it was in collision with a silver Vauxhall Astra at 6.30pm.

Tram services stopped for about 40 minutes while the line was cleared.

The female driver of the Astra was treated at the scene by paramedics.

The two police officers involved were unhurt.

This morning a BTP spokeswoman said: "There will be a full internal investigation, which will look at why they were where they were and the speed they were driving at.

"The woman's injuries are still unknown."