PART of Haslingden town centre was sealed off after a highly dangerous mix of chemicals leaked out of an old mill and into the street.

Fire chiefs said it was "only by luck" no-one was injured by the yellow substance, found to be a mix of caustic soda and hydrochloric acid.

They believe youngsters may have broken into the boarded-up mill, knocking over two drums of the chemicals. An investigation into the source of the chemicals has been launched.

The chemicals - abandoned in the old Bellworks building - had corroded their metal containers and seeped into a path linking Deardengate and Blackburn Road.

People were alerted by the fumes and several streets were sealed off at around 7pm.

Around 30 firefighters were called to the scene, including crews from Accrington, an environmental support unit from Burnley and Lancashire's specialist chemical incident vehicle from Preston.

Analysts identified the substance, which can burn the skin and cause breathing difficulties and eye irritation, at around 9pm, and officers in chemical protection suits diluted the acid before washing it down a nearby drain.

They also broke into mill, once a base for Karrimor and other firms, to clear the building.

Assistant divisional officer, Peter Lockwood, said: "If a child had touched it or played with it, the consequences would have been very serious.

"It was probably used to clean heavy-duty kitchen equipment and then left behind by whoever used to rent that part of the building."

He added: "The reason the immediate area was cordoned off was to make sure that no-one got too close so there was no risk of the chemicals being taken further out."

Firefighter Tommy O'Kane, from Accrington fire station, said: "The chemical can causing burning and when we got there was giving off fumes, which could also hurt the eye. We think youngsters had been playing in there, knocking over the drums to start everything off. It was a very dangerous thing to do."