FIREFIGHTERS are preparing to search for two people unaccounted for following an explosion in Abingdon.

Three large explosions and a smaller one rocked the area around Colwell Drive at about 1pm today.

A fire service spokesman said there had been explosions at a industrial unit in Blacklands Way and two people were unaccounted for.

Firefighters are damping down the building - which has not been identified publicly yet - to make it safe before they go searching for the two people.

The spokesman added this did not mean they were definitely inside the building, just that their whereabouts were not known.

Colwell Drive is closed and is expected to be shut for some time.

One person living in Faringdon Road said: "It really shook the whole house.

"It really startled me."

A staff member at business AHF, in Colwell Drive, added: "We just heard two big bangs. The windows shook and we thought it must have been a gas cannister exploding."

He said the explosions were so forceful that he initially thought they had happened at AHF.

Shops at the nearby retail park were evacuated.

A spokesman at Homebase said: "Police came into the store at 1.30pm and told us to clear everyone out.

"They said there had been an explosion at a chemical plant and that more canisters could go up at any time."

He said both Homebase and B&Q had been evacuated. Staff at Homebase were then allowed to return but all shops at Fairacres Retail Park have now been evacuated.

An ambulance spokesman has said there had been no reported injuries to paramedics yet.

A fire service spokesman said there were up to 70 firefighters at the scene, along with police, paramedics and the Environment Agency.

He described it as "a relatively large incident".

He added: "Fire and rescue service crews were on scene within minutes of the explosion and immediately began defensive firefighting with ground monitors and establishing a dynamic safety cordon.

"We are currently extending the safety cordon to 300 meters in partnership with other emergency services and we urge local people to stay away and co-operate with all services.