Police are investigating 25 linked incidents of criminal damage across Salford and believe houses in multiple occupation (HMOs) are being targeted.
The incidents, including smashed windows, vandalism and graffiti, have been reported since 5 October and each incident follows a similar pattern of offending, Greater Manchester Police (GMP) said.
The force said the attacks on homes were in different parts of the city but they were currently being treated as linked.
The most recent incident was reported on Tuesday evening.
Ch Insp Lee Gridley said inquiries so far had led officers to believe “HMOs, and properties that have been mistaken for HMOs, are being targeted”.
“No one should be made to feel unsafe in their own home and it’s not something that will be tolerated in Salford, or anywhere in Greater Manchester,” he said.
Officers will be carrying out patrols across Salford throughout the week while investigations continue.
Detectives are trawling through CCTV and monitoring social media coverage of the incidents.
A 13-year-old boy who was arrested as part of an investigation on 8 October has been released on police bail.
GMP is urging anyone with information or footage to come forward.