TWO men were injured in an explosion at a West Thurrock chemical plant which “shook” nearby houses.

Fire crews were on stand-by for two hours as experts at Industrial Chemical Ltd on Stoneness Road assessed a leak of caustic soda.

It is thought the explosion came from within a chlorine scrubbing unit, shortly after 8pm on Thursday.

Essex Police advised residents living nearby to stay inside and close their doors and windows as a strong smell of chlorine wafted through the air.

At 10pm, Divisional Officer Neil Fenwick said: "We have had assurances from chemical experts on site that there is no risk to the public.

"A small tank of diluted caustic soda exploded and the contents drained away into an interception tank and was contained on site."

Police closed Oliver Road in both directions while work was carried out to make the site safe.

Two workers suffered minor injuries. One, who had a leg injury, did not require ambulance treatment but the East of England Ambulance Service said one person was treated at the scene.

Just after 10pm, police and fire crews declared the site safe and announced there was no risk to the public. The Health and Safety Executive have been informed of the incident.

A number of people reported on social networking site Twitter that the explosion “shook houses” and could be heard as far away as Aveley, Corringham and Bexleyheath in Kent.

At 9.30pm, a spokesman for Essex Police said on the force’s Twitter feed: “Explosion caused loud bang at chemical plant in Stoneness Road West Thurrock about one hour ago. Strong chlorine smell in area.”

Daniel Campbell, of London Road, said on Twitter: “Our house shook. Sounded like a bomb went off. Everyone in the street was out to see what happened.”

Kirsty_xo said: “Chlorine gas explosion in Thurrock. Made the doors shake at work!”

Eunice, also on the social networking site, said at 8.15pm: “Something has just gone bang in west Thurrock. Thought my front door was being kicked in.”

Industrial Chemicals Ltd supply water treatment chemicals, flocculants and detergents to a variety of industries across the UK and Europe.