Around 30 firefighters as well as police and paramedics are at the scene where homes have been evacuated following the blast and hospitals have been put on standby to handle the casualties.

Emergency services were alerted to the explosion in Cloes Lane at around 8.30am, which sparked a gas-fuelled fire at a semi-detached house, ripping through the neighbouring property. Several other homes were damaged and affected by flying debris.

The sound of the explosion brought neighbours out onto the streets

Residents described hearing a "horrendous" blast which shook their homes and forced them out onto the streets.

One, Stuart Coe, said some of the debris landed in a school playing field, and neighbours initially helped tend to the injured.

He said: "We just getting the kids ready to go out this morning. We were sitting there having breakfast and the next thing we heard this almighty bang and literally everything shook in the house. All the neighbours just came running out their houses.

"It was almost like a bomb going off. The kids were upset and crying because we didn't know what was going on. And then we started fearing there had been an explosion and one of the neighbours believes she saw British Gas in the area yesterday.

The explosion destroyed two semi-detached properties in Cloes Lane

"We knew it was pretty serious when we saw the first air ambulance ... absolutely horrified when we saw the second.

"There is a police helicopter and we are hearing fire engines up and down the road - it's pandemonium.

"We could see smoke within minutes of the explosion. It was a pretty nasty event. It is unbelievable," he added.

Essex Fire and Rescue Service tweeted the explosion "flattened two houses and badly damaged a third", but everyone was accounted for.

Cloes Lane residents rushed out their homes upon hearing the blast

Residents have been told to get out their homes and to leave the area which has been cordoned off by police while firefighters, aided by dogs, search through the rubble and gas board officials examine the scene.

Some 19 properties have been evacuated, 10 in Cloes Lane and nine in Dedham Avenue.

The electricity has also been turned off in Cloes Lane, which Essex Police said would affect "the whole street for some time".

An Essex Police spokesman said: "Several houses have been damaged. The immediate area is currently being evacuated. People are advised to avoid the area while emergency services deal with the scene."

The houses in Cloes Lane before this morning's explosion

Resident Stuart Coe describes what happened: