Increased levels of natural gas in the ground have been identified after a fatal explosion at a house in Bedford, police have said.

A neighbour said they heard a “mighty bang” and the roof “came off” in an explosion and fire at a house on Saturday that killed one person.

A second person was taken to hospital with serious injuries after the incident in Cleat Hill, Bedfordshire Police said, in a post on social media.

The immediate area around Cleat Hill has been evacuated and people have been advised to avoid the area as work at the scene continues, police added.

In a statement on Sunday, police said: “Following the explosion and subsequent identification of increased levels of natural gas in the ground, an evacuation of the immediate area has been undertaken and a cordon and road closures remain in place as a precaution.

“The gas levels identified are thought to be naturally occurring gasses from an underground source and not coming from the gas pipe network in the area.

“Safety is our main priority, and so we are still advising for people to avoid the Cleat Hill area whilst work at the scene continues.

“We also want to remind any drone owners that the area is currently a no-fly zone.

“We know that residents of nearby properties want to get back into their homes as quickly as possible and we thank them for their continued support and patience.

“We are working closely with multiple partners as part of our investigation into the circumstances and our thoughts remain with the family and friends of the person who sadly died and the person who is being treated in hospital.”

A neighbour, who did not wish to be named, said that natural gas had been discovered “coming out from the ground” in June during some building work nearby.

She said: “From what I heard, when they went to drill deep for central heating, they discovered this hissing gas coming out from the ground, which is like natural gas, which was at the bottom of his garden.

“Who’s to say that this gas isn’t around anywhere else?”

She continued: “Now you’re on tenterhooks and you don’t know which house is going to go up.

“I’m quite elderly and I don’t want to live the rest of my years with this fear – it’s horrible.”

“My house was checked yesterday with a special gadget and there was no (gas) escape in my house because it monitors the natural gas and the other gas we have in the house.

“It’s a bit worrying, that’s all I know, and more than that, it’s very sad.”

She said: “I  just heard the bang, I heard a mighty bang that was really massive.

“I can’t describe it. I’ve never heard anything like it.”

The woman, who was evacuated from her home, said she thought initially the noise at about 7am was caused by something falling on her roof or a car that had come off the road.

She said the “whole roof” of the affected house “came off” in the explosion.

“Whatever was left of the roof went up in flames, I didn’t see the flames itself, when I went out it was more like smoke.”

Bedfordshire Borough Council has set up an emergency assistance centre for people who have been evacuated from their homes,  police said.

According to the Bedford Borough Council website, work was undertaken to address a gas leak in the area earlier in the year, after which the council said it was still looking for a long term-solution.

Officers remain at the scene, police said on Sunday.