Three people have been injured in a car bomb explosion outside a police station in Newtownhamilton, County Armagh, BBC reported.
The explosion happened at about 2325 BST. Police were told in a call to a Belfast hospital about an hour earlier that a vehicle had been abandoned.
Police were en route to the station, which is manned on a part-time basis, when the explosion happened.
The three people were taken to hospital in Newry with injuries that are not thought to be life-threatening.
Local residents said the blast could be heard eight to 10 miles away.
The town centre has been cordoned off and Newtownhamilton High School has been opened for residents who have had to leave their home.
Last week, the Army defused a car bomb outside the town's police station.
Earlier on Thursday, security sources told the BBC the threat posed by dissident republicans has risen to the highest level in 12 years.
Meanwhile, a pipe bomb has exploded behind a house in Chestnut Hill in the Brackaville area of Coalisland, County Tyrone at about 2330 BST on Thursday night.
A man and a woman, who were in the house at the time, were uninjured but a number of windows were damaged.