A group clearing out a house on Balfour Road in Southport thus afternoon had to call 999 after the discovery of an unusual object.
Emergency services attended the property, near to the junction of Forest Road.
The area has subsequently been closed off and a cordon remains in place.
Merseyside Police said: “We can confirm that officers are currently in Southport following the discovery of a suspicious item inside a flat today, Tuesday 2 June.
Just after 12.30pm officers were called after a suspected unexploded ordnance device was found while clearing the property on Balfour Road.
As a precaution, road closures are in place in the surrounding area and residents have been evacuated. A cordon remains in place and the Explosive Ordnance Disposal (EOD) have been called to assess the device.
Motorists and pedestrians are advised to avoid the area while emergency services deal with the incident. More updates will be provided when appropriate.”
Local bus services including the 44 have been diverted.