The RUC in Derry city is investigating incidents in the Shantallow area on Monday during which three houses were damaged in attacks.
Eight masked men carrying baseball bats forced their way into a house at Brookdale Park just before 9 p.m. and damaged furniture. A couple and their three children, aged between seven and 10, were not injured.
A short time later, the gang is believed to have damaged an unoccupied flat in the nearby Carnhill Estate. Similar damage was caused to an unoccupied house at Glengalliagh Park.
Detectives are linking the attacks to an incident in the same area on Sunday when a shot was fired through the window of a house. An RUC spokesman ruled out sectarian or paramilitary involvement.