Gardaí and the PSNI are hunting a gang believed to be responsible for a series of car hijackings in counties Down and Armagh before crossing into the Republic.
The gang tied a rope around the neck of an elderly man and forced him to drive them across the Border to Dundalk.
Gardaí are investigating a link between the gang's activities in the North and the later hijacking of an 81-year-old woman who suffered a serious leg injury when she was dragged from her car by a gang of youths.
The incidents began when it was reported to police that a car, possibly stolen, had been set alight in Newcastle, Co Down, just before 4am yesterday.
Just over an hour later, a silver Vauxhall Astra was stolen from Tullymore Forest Park, in the foothills of the Mourne Mountains outside Newcastle.
The owner of the car was asleep in his caravan at a woodland caravan site when he was assaulted, suffering facial injuries, and had his car keys stolen.
Just after midday a woman was driving along the Newtownhamilton to Belleek Road in South Armagh when a silver Vauxhall Astra collided with her. The occupants of the Astra tried to hijack a VW Polo from a woman, failed, and then seized a VW Sharan car driven by a woman in her 50s.
The PSNI said a lorry blocked the road, forcing the thieves to crash the Sharan into a gully.
It is believed the gang then hijacked a black Renault Laguna driven by a man in his 60s, who was assaulted, had a rope tied around his neck and was ordered to drive across the Border to Dundalk.
Two of those involved were reported to be in their late teens or early 20s and to speak with strong southern accents. No one involved in the incidents north of the border were injured, although some were badly shaken, said a PSNI spokesman.
Newry PSNI district commander Bobby Hunniford said: "There is no doubt somebody could have been killed. These people were driving on the wrong side of the road when they hit a car containing a mother and her three children."
Newry and Armagh Sinn Fein councillor Jimmy McCreesh visited the woman whose vehicle was almost stolen with her child in the back.
"Her main concern was the fact that she had got her two-year-old child strapped into the back of the people-carrier. "
"She struggled with the guys to try to fob them off but she was unable to do so. They proceeded in dragging her out of the vehicle on to the ground. She was screaming and shouting for help and then somebody else came along and she was able to get the young child out of the vehicle."