1 of 3 | Sinn Fein leader Michelle O'Neill joined leaders from the other four main parties in Northern Ireland on Friday in issuing a joint message of solidarity with a police officer who is fighting for his life after being gunned down earlier in the week. File photo by Geoff Caddick/EPA
Feb. 24 (UPI) -- Detectives in Northern Ireland said Friday they had arrested a fourth man under the Terrorism Act in connection with the attempted murder of a senior police officer in Omagh.
The 22-year-old man was arrested 35 miles away near the town of Coalisland on suspicion of involvement in the shooting of Detective Chief Constable John Caldwell on Wednesday evening, the Police Service of Northern Ireland said in a news release.
He is currently being questioned by detectives.
Three other men aged 38, 45 and 47 years who were arrested yesterday, remain in police custody.
Caldwell, 58, who was shot multiple times by two gunmen as he coached a local under-11s soccer team at a sports complex, suffered life-changing injuries.
He remains critically ill and heavily sedated in hospital after he was gunned down in front of his son.
No one has claimed responsibility for the attack.
Police said yesterday that the principal line of investigation centered on dissident republican groups.
"We are keeping an open mind," PSNI Assistant Chief Constable Mark McEwan told a press conference.
"There are multiple strands to that investigation. The primary focus is on violent dissident republicans and within that, there is a primary focus as well on New IRA."
Caldwell is a well-known senior policing figure with a high profile from performing media duties as the lead officer on several high-profile cases, including dissident republican violence and gang murders.
The leaders of the five main parties issued a strongly worded statement condemning the attack and appealing to the public to assist the investigation.
"We speak for the overwhelming majority of people right across our community who are outraged and sickened by this reprehensible and callous attempted murder," the joint statement read.
"There is absolutely no tolerance for such attacks by the enemies of our peace. Those responsible must be brought to justice."
The statement was signed by Michelle O'Neill, of Sinn Fein; Jeffrey Donaldson, of the Democratic Unionist party; Naomi Long, of Alliance; Doug Beattie, of the Ulster Unionist party; and Colum Eastwood, of the Social Democratic and Labour party.
The so-called New IRA, a splinter group that sprang out of the IRA as it prepared to lay down its weapons as part of the Good Friday Agreement in 1998 that brought peace to Northern Ireland, has continued to target police officers.
In November, two police officers escaped injury when the New IRA detonated an improvised explosive device near their car in the town of Strabane 20 miles away from Omagh.
It was the first successful attack since PSNI officer Ronan Kerr, a 25-year-old Roman Catholic, was killed by a booby trap device planted outside his home in Omagh in 2011.
Omagh is the scene of the deadliest incident of the three-decade-long troubles when the New IRA detonated a car bomb in the town in August 1998 killing 29 people and injuring 220, the repercussions of which rumble on today.
Earlier this month, the British government launched a public inquiry into the bombing.