TWO men have been arrested on suspicion of arson after a huge explosion ripped through a block of flats in east London and left five people in hospital.

Ten fire engines and more than 70 firefighters rushed to the scene and 41 homes were evacuated after the blaze quickly spread.

The explosion happened at a block of flats in Ardleigh Green Road, Hornchurch, The Sun reports.

Emergency services dealing with explosion at block of flats in #Hornchurch, east London (via @allscores1) pic.twitter.com/niEJEASGZb — Global's Newsroom (@GlobalsNewsroom) January 23, 2017

Police confirmed two men had been arrested on suspicion of arson and both were taken to hospital for treatment to their injuries.

Eyewitnesses described “carnage” after the explosion at a block of flats in Ardleigh Green Road, Hornchurch with buildings shaking and “flames billowing” from the scene.

Reports on Twitter said debris from the blast was “scattered across the A127” after “window frames were blown 70 feet (21 metres)”.

A fire service spokesman said the incident took place in a three-storey block and 72 firefighters were called to the scene after receiving a report at 5.14pm (4.14am AEDT).

They confirmed four people were taken hospital while it is understood a fifth person admitted themselves.

One eyewitness - who did not want to be named - told Essex Live: “Allegedly there was a cannabis factory on the ground floor. One chap had two gas canisters that somehow caught fire.

“The fire brigade were called and in ten minutes there were loads here. It looks like he lost control of it.

“The window frames were blown 70 feet (21 metres).”

We are currently still on scene in #Hornchurch at a building fire and explosion with @LondonFire pic.twitter.com/hDjjqQR73F — LondonAmbulance HART (@LAS_HART) January 23, 2017

The Met declined to comment on the claims and said it “would not speculate” on the cause.

Witness Jason Smedley, 46, was in his office at the time of the explosion.

He said: “We felt the whole building shake,” adding that he could soon see “flames billowing”.

Mr Smedley said the front of the flats had been “blown out” across the road.

He added: “We pulled people back and told them to get out of the way.

“Unfortunately there was a woman and her daughter, that were in the flat above, that heard the explosion, ran out, and we brought them back ... had just their dressing gowns on, so we just gave them tea and blankets. They’ve got nowhere to live tonight.”

For more see The Sun.