Seventy firefighters were needed to tackle a blaze at a factory after flames engulfed a stock of batteries and caused them to explode.

The firefighters, using 10 water pumps and support vehicles, battled for more than three hours to bring the fire, at Ultralife Batteries in Abingdon, under control.

Crews from the town discovered a fire in a ground-floor store, containing lithium-based batteries, at about 2.40am on Saturday.

They managed to bring it under control -- but some of the batteries had been set alight and began to blow up.

Explosions lasted for about an hour. One firefighter was knocked to the ground by the force of an explosion.

Colin Thomas, brigade commander, said: "Some of the explosions were so loud it's likely people heard them across Abingdon.

"There is a difficulty for us with lithium because it reacts explosively with water. During the explosions, we had to use defensive firefighting from outside the building.

"One of the initial explosions was so ferocious that it affected fire crews and one firefighter was blown off his feet. Thankfully, he was not seriously injured and stayed to help tackle the fire."

Security guards based about 500 yards away in Abingdon Business Park told the Oxford Mail they heard the explosions and saw smoke billowing from the building in Nuffield Way.

One, who asked not to be named, said: "Luckily, it happened during the night-time when it's quiet."

Crews wearing protective chemical outfits managed to douse the fire at 5am with water jets and worked throughout Saturday morning to investigate the cause.

Police and paramedics from Oxfordshire Fire and Rescue attended, but there were no casualties.

Mr Thomas said a chemical expert, a Vale of White Horse District Council building officer and an Environment Agency officer were called to help.

Tests to find out whether the building was structurally safe were expected to continue today (June 7).

Mr Thomas said: "There were two areas affected, one about 10m by 20m and the other, where the explosions happened, about 20m by 20m.

"Luckily, we were alerted by an automatic detector early on and due to protective internal walls and pro-active firefighting the fire was contained as much as it could be."

In April, firefighters extinguished a pile of burning cardboard in a skip next to the three-storey warehouse, which is used for research.

No-one from Ultralife Batteries was available for comment.