A builder is in hospital with serious burns after an explosion at Croydon Police station.

The explosion took place in a firing range in the basement of the Park Lane station, injuring seven, at 11.25am today (March 20).

A man was flown by air ambulance to Broomfield Hospital in Chelmsford with serious burns, while a second man was taken to St George’s Hospital with burns to his arms and face.

A man with minor burns, and a woman and man suffering from smoke inhalation, were taken to Croydon University Hospital while two others were treated at the scene.

Four of those injured were contractors, including those with burns, while two were civilian staff and a single police officer.

Ten crews, 50 firefighters, from across the borough fought for more than two hours to contain the fire to the basement area.

More than 100 staff were evacuated while 14 held in police custody were moved to South Norwood Police station.

London Fire Brigade Station Manager Tej Ajimal, who attended the incident, said: "Crews worked hard to bring the fire under control and managed to contain it to the basement area and stop it from spreading to the rest of the police station."

The incident happened just two days after the station was reopened to the public following a major refurbishment.

Work on the firing range, which is used by forces across London, was due to begin on Tuesday.

Chief Inspector Caroline Trevithick called a press conference shortly after the fire was brought under control.

She confirmed there was no live ammunition in the basement due to the scheduled work.

She said: "This is an industrial accident in the basement of our police station.

"The Health and Safety Executive has been contacted and will conduct an investigation."

Witness Celia Roberts walked past the incident shortly after noon.

She said: "There are ambulance sirens going off everywhere. There are lots of fire engines and police running around outside.

"No-one appears to know what is happening."

A large cordon was established and police closed Park Lane southbound and Friends Road.

Click here to follow our LIVE blog of developments at the scene in Croydon

Click here to view a picture gallery from the explosion at Croydon police station