A massive explosion has rocked a fertilizer plant near Waco, Texas. Dozens are feared dead and at least 172 were injured in the disaster.

More than half of the town has been evacuated and people are still being pulled from damaged buildings following the blast in West, near Waco.

The blast – which the US geological survey said had a 2.1 magnitude – was so powerful that a nearby block of flats was destroyed and 130 residents of a local nursing home were injured

As many as 75 homes were damaged by the blast as well as a local school.

A number of people are also suffering from “respiratory distress due to chemical inhalation”.

Officials have said firefighters have stopped trying to tackle the blaze as there are fears of another explosion.

The explosion happened shortly before 8pm local time on Wednesday and could be heard as far away as 45 miles.

Tommy Muska, West’s mayor, said a number of firefighters are unaccounted for.

He told CNN: “It’s like a nuclear bomb went off.”

Sergeant William Swanton, from Waco Police Department, said there were scenes of “extreme devastation”.

“We’re going house to house, business to business, and we’re seeing quite a bit of devastation in the area of the plant.

“They’re still pulling victims out, still bringing victims to triage.

“There may be firefighters that are unaccounted for and potentially a law enforcement officer as well.”

He also said that a helicopter which was helping with the rescue operation was damaged.

Texas Governor Rick Perry said: “Our thoughts and prayers are with the people of West, and the first responders on the scene.”

Debby Marak told The Associated Press she noticed a lot of smoke coming from the area across town near the plant, which is near a nursing home.

She said she drove over to see what was happening, and when she got out of her car two boys ran towards her screaming that officials told them to leave because the plant was going to explode.

Moments later the blast happened.

“It was like being in a tornado,” the 58-year-old said. “Stuff was flying everywhere. It blew out my windshield.

“It was like the whole earth shook.”

Police officers have reportedly been transporting the injured to local hospitals in their patrol cars.

As many as a dozen helicopters have been sent to the West High School stadium where ambulances are waiting to transport victims to hospitals.

Glenn Robinson, chief executive of Hillcrest Baptist Medical Centre, in Waco, told CNN his hospital had received 66 injured people for treatment, including 38 who were seriously hurt.

He said the injuries included blast injuries, orthopedic injuries, large wounds and a lot of lacerations and cuts.

American Red Cross crews from across Texas are being sent to the site.

The explosion comes on the eve of the 20th anniversary of the Waco siege – a deadly confrontation between federal authorities and heavily armed locals.

The Dallas Morning News said that the fertiliser company previously reported to the US Environmental Protection Agency and local public safety officials that there was no risk of fire or explosion at the plant.

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