Three people have been arrested after two suspicious devices were found at a flat.
Police raided the address on Grasmere Crescent in Winton, Salford, at 11.35am.
A bomb disposal team was sent to make the devices safe as surrounding homes were evacuated.
The incident is not being treated as terror-related.
A Greater Manchester Police spokeswoman said: "A search of the address by specialist officers is ongoing. A cordon will remain in place as a precaution until the search is completed and a number of nearby addresses have been evacuated.
"Two men and a woman have been arrested on suspicion of possession of explosive substances under the Explosive Substances Act. They remain in police custody for questioning."