Northern Irish police have arrested a fourth man early on Friday in relation to the attempted murder of a senior detective shot in front of his son in the town of Omagh.
Northern Ireland police chief Simon Byrne said on Thursday three men had been arrested following the shooting of the senior detective.
Detective Chief Inspector John Caldwell is in critical condition having undergone surgery overnight. He was shot a number of times by two gunmen while putting footballs in his car after finishing a coaching session with an under-15 soccer team.
While a 1998 peace deal largely ended three decades of sectarian violence in Northern Ireland, police officers are still sporadically targeted by splinter groups of mostly Irish nationalist militants opposed to Britain's rule over the region.
"The investigation is at an early stage. We are keeping an open mind at the moment. Our primary focus is on violent dissident republicans and within that a group called New IRA," Assistant Chief Constable Mark McEwan said.
The four men aged 22, 38, 45 and 47 arrested under the Terrorism Act are currently being questioned by detectives.
The New IRA has targeted police before and was responsible for the killing of journalist Lyra McKee in 2019.
It is a much smaller group than the Irish Republican Army, which disarmed when the Good Friday accord ended the fighting between nationalist militants seeking unity with Ireland, and pro-British unionists wanting to stay in the United Kingdom.
The UK last year lowered its Northern Ireland-related terrorism threat level for the first time in more than a decade, with police saying at the time that operations against nationalist militants were making attacks less likely.
The threat from domestic groups was reduced to "substantial" from "severe", meaning an attack is still likely, according to an independent assessment by the MI5 domestic spy service. McEwan said the police continue to review the threat level.
The last time a police officer was shot in Northern Ireland was 2017. The last police officer to be killed, Constable Ronan Kerr, died when a bomb exploded under his car outside his home in Omagh.
"ENEMIES OF THE PEACE"
The shooting was condemned by the governments in Dublin, London and Washington.
A statement by the leaders across Northern Ireland's political divide said the people of Omagh had endured profound suffering and trauma in the past and there was "absolutely no tolerance for such attacks by the enemies of our peace".
"Society has moved on in Northern Ireland," Britain's Northern Ireland Minister Chris Heaton-Harris added. "There is no place for violence like this."
In Washington, the U.S. State Department spokesman said "the victim's service both in uniform and off duty stands in what we believe to be stark contrast to the perpetrators, who offer nothing to the communities they so falsely claim to represent."
Police said the gunmen continued to fire while Caldwell was on the ground after running a short distance. Both gunmen fired multiple shots and at least two other vehicles were struck in a crowded car park where parents and children ran for safety.
The suspects' car was found burnt out just outside Omagh.
Caldwell, a serving police officer for 26 years, has been a senior detective for a number of years and has investigated a lot of serious crimes and terrorist activity, Police Federation for Northern Ireland Chair Liam Kelly said.
"Unfortunately this is a stark reminder for our colleagues that 25 years on from the signing of the Good Friday Agreement, policing in Northern Ireland is still a very dangerous occupation and carries extreme risk," Kelly said.
(Reporting by Amanda Ferguson, Writing by Padraic Halpin; Additional reporting by Rhea Binoy; Editing by William James, Nick Macfie, Raissa Kasolowsky and Andrew Heavens)
