A major Police Operation is underway after a man was spotted by a member of the public going into a disused brewery in Sheffield.

A large number of police officers have been deployed to the Neepsend Lane area of Sheffield and placed the area on lockdown.

Major disruption in the Neepsend Lane area as police search for a gunman in the old Stones Brewery @BBCSheffield pic.twitter.com/uSAvvyksCl

— Andy Kershaw (@andyksheffield) July 29, 2016

The incident is expected to have a significant impact on traffic and pedestrians in the area as police have closed a number of roads.

Police received reports at 5.15am that a man had been spotted with what was believed to have been a firearm entering the disused brewery.

A police spokesman said: “Please avoid this area this morning if possible as traffic will be significantly heavier than usual and delays are very likely.”