Two gunmen went to a house in the Ballymagroarty area of Londonderry on Tuesday (April 29) in search of an individual who turned out not to be in, according to the Police Service of Northern Ireland (PSNI).
The incident occurred at Merriman Court shortly after 10pm.
The masked men went into a house which was occupied at the time by a woman and her children. They shouted the name of a man, who was not there.
No shots were fired and no injuries caused.
At this stage a motive has not been established.
The men were wearing dark hooded tops and ran off afterwards and police are keen to hear from anyone who saw them, or vehicles, in the area.
Anyone with information on the incident is asked to call police on the 101 non-emergency number, or contact the Crimestoppers charity anonymously on 0800 555 111.