A gunshot was fired through the window of a house with a 65-year-old woman and her three young grandchildren inside.
Police in Salford have launched a major investigation.
No one was injured, but a senior detective called the shooting 'an extremely frightening event for all involved'.
Police patrols have been stepped up in the Walkden area as a result.
GMP said officers were called to 'reports that a firearm had been discharged through the window' of a property on Windale, a cul-de-sac off Hilton Lane, at 10.15pm on Saturday night.
Police said they believe it was 'an isolated incident'.
A force spokesman said: "No arrests have been made and an investigation is underway."
A police cordon was set up on Windale and Hilton Lane and forensic investigators attended the scene.
Inspector Katie Allen said: "This was an extremely frightening event for all involved, especially as there were young children present at the time.
"I would like to reassure the community that we are doing all we can to protect residents and investigate this incident.
"Additional high-visibility police patrols will be present in the coming days to ensure the safety of those in the area."
Officers are appealing for anyone with information to come foward.
Det Insp Allen said: "We are appealing for anyone who may have witnessed anything or has any information about this firearm discharge to get in touch with police as soon as possible.
"No matter how insignificant you may feel the information is, it could prove vital in helping us with our enquiries."
Call police on 101, quoting incident number 2894 of 21/03/20 or Crimestoppers on 0800 555 111.
