Around 70 firefighters were tackling a blaze next to a train track.

Ten fire engines were called to the railway arches on Union Street in Southwark this morning which is causing disruption on lines heading into London.

The train line between Waterloo East and London Bridge was blocked but as of 12.20pm had been reopened although there are still delays.

Southeastern – which runs services from Kent along the line – said trains were being diverted to other London Terminals or terminated at alternative locations.

A spokesman for Network Rail added: "Sorry to say, no sooner had we fixed the points between Waterloo East and London Bridge than a fire broke out in an arch under railway.

"London Fire Brigade are on site with multiple pumps and we have closed the railway until we can confirm it is safe.

"We will need to inspect the railway once the fire out before we can reopen. Thank you for bearing with us."

The London fire service was called at 9.29am and crews from Dowgate, Whitechapel, Shoreditch, Shadwell and surrounding stations were at the scene.

Videos of the blaze showed black plumes of smoke billowing over the railway line.

Station Commander Wayne Johnson, who was at the scene, said: "The blaze was producing heavy smoke and those living or working in the local area were advised to keep their windows and doors closed.

"Trains to and from London Bridge are affected and several buildings were evacuated."

Officers from the British Transport Police confirmed they were assisting the fire service and a cordon has been put in place on America Street and Great Suffolk Street.

As of 10.35am, the fire had spread to a car park and a couple of electric cars were ablaze.

By 11.20am it was under control but crews are still at the scene.

Southeastern told passengers at around 12.20pm that all lines have reopened but trains will continue to be altered or cancelled whilst it works to get the service back to normal.

There are currently no reports of injuries.

Firefighters also investigated smoke coming from a platform at London Bridge Underground Station and confirmed this was coming from the fire on Union Street.

The Brigade's 999 control officers have taken more than 33 calls to the blaze. They were able to use 999Eye to live stream the fire from a smart phone to screens in the control room, allowing for greater visibility of the incident.

The cause of the fire is under investigation.