Police in Northern Ireland say a viable device discovered last night is believed to have been part of 'an attempt to murder police officers'.
It happened in Craigavon in Co Armagh.
At around midnight, the PSNI received a report of a 'loud bang' in the Tullygally Road area.
Shortly after police also heard from a Belfast-based newspaper.
The paper reported they had received a call claiming a device had been fired at a police patrol but missed its target.
Officers and a bomb disposal team attended the scene, where they discovered a suspicious object.
It was later confirmed to be a viable device.
A security operation was launched and that is continuing this afternoon.
In a statement, PSNI chief inspector Barney O'Connor said: "At this stage we believe the device to be viable and that this was an attempt by dissident republican terrorists to murder police officers.
"At present it is unclear if the device was fired at a passing patrol or if this attack was set up in such a way as to target those local police officers responding to the area following reports from the public."
He added: "I cannot condemn strongly enough those behind this cowardly and despicable act of terrorism.
"They offer nothing to this community and their actions here do not reflect the wishes of the vast majority of the law abiding residents of this area."
Police say the device will be removed for a forensic examination.