A cordon is currently in place at an address in Ramsbottom.
Officers attended the property on William Street to carry out a pre-planned warrant this morning (Wednesday, November 6th) and a cordon has been established around the property following the discovery of what appears to be to be a small homemade explosive device inside the address.
The Explosives Ordnance Department are attending.
A number of nearby properties have been evacuated as a precaution and a number of roads are closed and diversions put in place.
There are rest centres at the Rostron Arms pub at Edenfield and Haslingden Sports Centre, Helmshore Road, if people need somewhere to go until the incident is concluded.
Supt Stasia Osiowy, of East Police said: “We have evacuated a number of properties as a precautionary measure but there is not believed to be any immediate threat. We will endeavour to return people to their homes as soon as possible.”
Three people have been arrested on suspicion of manufacturing explosive devices and are currently in custody.
Enquiries are on-going.