Army bomb experts have made safe a pipe bomb thrown into a police base in west Belfast.
The pipe bomb was found on the station roof
The device was discovered on the roof of a building at the Woodbourne police complex at about 1100 GMT on Wednesday.
A police spokeswoman said they were trying to establish when the device was thrown.
It comes in the wake of a blast bomb attack on Antrim Road police station in the north of the city.
The police said a caller claiming to represent the Continuity IRA admitted that attack.
Part of the Antrim Road was closed off as security forces examined the area shortly before 2200 GMT on Tuesday.
The devices were thrown into the front yard of the Antrim Road station.
One exploded causing slight damage to a window grill. The other failed to go off. A number of officers were treated for minor injuries.
Army experts deal with device at Antrim Road
Army bomb disposal experts were called to the scene to examine the second device.
Residents of a nearby hostel for people with drug and alcohol problems were moved to another hostel nearby during the alert.
Meanwhile, a pipe bomb attack in County Londonderry was probably linked to loyalist in-fighting, the police have said.
The device, which was found in the back garden of a house at Leckagh Drive in Magherafelt, exploded at about 2300 GMT on Tuesday.
Three children, all under the age of six, who were sleeping upstairs escaped injury.
The yard and a neighbouring house were damaged.
PSNI district commander Terry Shevlin said the pipe bomb could have killed someone.
He appealed for help in trying to catch the perpetrators.