Humberside Police say the live device was found on Rawcliffe Road in Goole.
Residents have been evacuated and businesses have been forced to close after an unexploded Second World War bomb was uncovered on a street.
Humberside Police said the live device was found on Thursday morning on Rawcliffe Road in Goole, East Yorkshire, and shops and roads in the vicinity have been closed.
A no-fly zone has also been enforced over the area, and people living nearby have been told to stay indoors.
Humberside Police said the Explosive Ordnance Disposal (EOD) team confirmed the bomb was live on Thursday evening and experts are preparing to detonate it.
The force said it had not been detonated by 3.30pm on Saturday, but they expected it would be by the end of the day.
A spokesperson said: “As a precaution, and to allow the EOD team to complete their preparatory work before they safely dispose of the device, an area of extended cordon is being enforced.
“Restrictions will stay in place until the device is successfully detonated, anticipated some time on Saturday.”
“Those living or staying in the wider immediate area are asked to remain indoors,” the force added.
“Businesses within the cordoned area will be asked to close until the works have been completed.”
The east and west-bound carriageways of the M26 between junctions 35 and 37 have been closed, along with a section of the A614.
Published: by Radio NewsHub