The cause of two large gas explosions near a Bradford restaurant, which sent a fireball 40ft into the air today, is under investigation.

Residents and traders working nearby described how buildings shook when two cylinders containing liquefied petroleum gas caught fire and ripped through a storage container at the back of Sunrise Restaurant in New Otley Road today.

Police sealed off the area for almost three hours while firefighters checked to make sure there was no danger of further explosions. New Fields Drive, Heap Lane and Otley Road were all closed to traffic.

Imran Khaliq, who owns Nuttall Superstore in Nuttall Road, behind the storage unit, said: “I heard an explosion and the whole shop moved. I thought a car had gone into the building. I went outside and saw a fire blazing and then it went up again, there was another explosion.

“I could feel the heat from it. People felt the tremor right at the bottom of the street. The whole building shook.”

Daniel Atkinson, who was renovating a house in Heap Lane, said: “It was really loud.

“There’s no ceiling up here so all the dust was shaken down.

“I walked up the road and there were flames and you could hear the gas canisters hissing and then flames shot about 40ft into the air.”

Rob Whittaker, watch manager at Idle fire station, who attended the fire, said a welder working inside the container had accidentally set fire to rubbish outside and the flames had spread to the cylinders nearby.

The welder noticed the fire and had left the container before the explosions. Bradford firefighters arrived at the scene minutes before the second explosion.

Mr Whittaker added: “If anyone had been inside the container or walking nearby they would have been killed. These cylinders are extremely dangerous when involved in fire.”

Mr Ali, the restaurant’s owner, said he did not know how the cylinders came to be outside the storage container.

He added: “It has affected our business because usually we are quite busy here. We don’t know what caused the explosion but we don’t store any gas canisters.

“The safety of our customers is paramount and we are working alongside the emergency services to make sure there is no risk to our customers.”

John Blanchfield, Bradford Council’s environmental health manager, said: “Our health and safety team has been carrying out an investigation into the incident.

“Once they have reported we will decide whether or not any further action needs to be taken.”