Viable pipe bombs have been made safe in west Belfast and Strabane, County Tyrone.
A number of residents were moved from their homes during a security alert in Coolnasilla Park West which ended at about 07:55 BST on Sunday morning.
PSNI Det Insp Paul Rowland said: “Those who left this device in a residential area clearly have no regard for the people who live here.”
Elsewhere, a viable pipe bomb was made safe in Strabane’s Drumrallagh area.
Sinn Féin MLA Alex Maskey said the incident in west Belfast was part of “an ongoing attack on a particular family”.
He said: “The family are convinced that this is an act of intimidation.
“I’ve been asking the PSNI to make to sure we have a thorough and speedy investigation into this incident to establish who is responsible and to get them behind bars.”
Meanwhile, in a separate incident, a number of people were moved from their homes in the Drumrallagh area of Strabane during a security alert.
Police said a viable device that was left near a vehicle was made safe by army bomb experts and taken away for further examination. It followed a report at 11:00 BST on Sunday.