Detectives are working to establish whether a firearm was used in a disturbance which left a Sunderland home's window shattered.
Northumbria Police said at around 9pm yesterday, officers received a report that windows had been damaged at an address on Fordfield Road on the Ford Estate in Sunderland.
The house is in a stretch of homes near to Poole Road junction and opposite Blackies Field.
A force spokesman said: "Officers attended the scene but those responsible had fled the area.
"Nobody was injured during the incident.
"At this stage police believe the damage was caused by an unknown object being thrown at the window but police are aware of reports that those responsible were in possession of a firearm.
"Inquiries are ongoing to establish exactly what has happened and to confirm that those responsible were in fact in possession of a firearm.
"Patrols are in place in the area this afternoon to reassure any concerned members of the public and residents are encouraged to approach them if they have any questions."
Anyone with information is encouraged to contact police on 101 quoting log 1162 30/09/18 or Crimestoppers anonymously on 0800 555 111.