Police blocked off a half-mile danger zone as smoke from a suspected arson attack on a factory billowed across a town centre.

The fire broke out at car parts manufacturer BTR Brakes, in North Street, Lewes, at 4.10pm yesterday and continued into the evening.

Flames and smoke could be seen a mile away. Six fire engines were sent to deal with the blaze.

Firefighters feared there could be asbestos in the building so the police blocked off roads for about a quarter of a mile in each direction to stop people being exposed to any toxic dust.

The roof of the building is made of asbestos sheets. Environment Agency officials were brought in to check water used to fight the fire was not contaminated and could not affect local water sources.

Gas and electricity supplies were cut off.

Water was used to keep a large propane cylinder at the back of the building and an oxyacetylene blow torch inside cool and stop them exploding.

Brian Mitchell, 53, of Southdown Road, Portslade, Brighton, saw the fire while visiting nearby Tesco supermarket.

He said: "I haven't seen any major explosions but there have been some bangs and blue lights, like an electrical fire."

Dominic Lyons, who runs Just Trading newsagents in High Street, saw the fire unfold.

He said: "There were huge plumes of smoke in the air and small explosions all over the place."

Firefighters are still trying to determine the cause of the blaze, which could have been fuelled by brake fluids and other accelerants stored in the building.

Inspector Andy Kille, of Sussex Police, said the sealed off area had been made a crime scene in case there was any evidence to preserve.

Andy Gausden, station manager at Roedean, said firefighters were still tackling deep pockets of fire at 10pm.

He said: "We'll be here all night damping down and putting out hot spots, making sure it doesn't flare up again."

He said the police and fire service would decide whether the cordons blocking off the Phoenix Industrial Estate could be taken down by this morning.

Police have arrested a local youth in connection with the incident.