A device has exploded in Northern Ireland, police said.

The incident followed a security alert in Armagh during which residents were evacuated.

Local politicians said component parts of a bomb were recovered and a number of cars at a dealership were damaged.

On March 4, a prison officer was injured when a bomb exploded under his vehicle in Belfast. The dissident republican New IRA claimed responsibility.

Police Service of Northern Ireland (PSNI) detective inspector Will Tate said officers received a report of damage caused to four cars in the yard of a business premises just after 7.20am.

He said: "On further investigation it was thought that the damage was caused by an explosion.

"Further reports and investigations since then lead us to believe that the explosion occurred at approximately 12.40am and that the device was left by a person carrying a backpack at approximately 12.30am."

Bomb disposal experts have described the object as an improvised viable pipe bomb-type device.

"Today we are lucky that we are not dealing with a serious injury caused by this device and the reckless actions of the person or people behind it."