FIREFIGHTERS were unable to identify the source of a smell which led to them closing off South Parks Road on Monday.

The road was shut at about 8.30pm after reports of a “strong chemical smell” at Oxford University ’s Inorganic Chemistry Laboratory. It was reopened three hours later.

A fire service spokesman said the smell was not considered hazardous.

The university said no gas or chemical leak was found and the building, which was evacuated, was reopened at midnight.