Up to a hundred people have been evacuated after a chemical spill in Sunderland.

Fire crews and police were alerted shortly before 11am this morning that a chemical reaction had occured causing a spillage.

Pressure built in a drum containing as yet unknown chemicals at Onyx Scientific at Enterprise Park East at Silverbriar in Sunderland.

A Northumbria Police spokesperson said: "Police were called at approximately 10.50am by the Tyne and Wear fire and rescue service to assist following a chemical spill at Sunderland Enterprise Park.

"A 200 metre cordon has been placed around the site.

"Several businesses were evacuated with up to 100 staff members having to leave the area.

"Some people made their own way home while others were taken by bus to a nearby community centre."

A Tyne and Wear Fire Spokesman said: "A reaction inside a drum caused pressure to build.

"It is unclear what chemicals were involved but the reaction caused the formation of hydrogen gas."

"There is currently no spillage and seven appliances are on standby waiting for specialists to arrive from the company Chirex in Dudley.

"Specialist equipment will be used to release the pressure."

Onyx Scientific provides a wide range of chemical services to the life sciences industry.