A fourth man has been arrested by police in Northern Ireland investigating the attempted murder of two police officers in Co Tyrone.
The 38-year-old man was arrested in the Strabane area today.
Police earlier arrested three men, two aged 36 and another aged 28, under the Terrorism Act after conducting a number of searches in Strabane last night.
The two officers had been on patrol on Thursday at Mount Carmel Heights when a bomb was detonated at the side of their vehicle, prompting police to pursue a "strong line of inquiry" into whether the New IRA were involved.
PSNI Assistant Chief Constable Bobby Singleton earlier said the location of the incident in Strabane and previous attacks made the involvement of the dissident republican splinter group a possibility.
Neither officer was injured in the attack, which caused a major security alert in the area, affecting more than 1,000 residents and leaving some children unable to get to school yesterday.
Police have said they have discovered what could be a command wire for the improvised explosive device during follow-up searches.
Mr Singleton said the officers who had been conducting routine patrols over ongoing antisocial behaviour in the area were left "shaken" when they saw a flash and heard a loud bang.
"They left the area, came back to the station and they found evidence of some blast damage to their police vehicle," he added.
"Our thoughts are first and foremost with the two police officers who were here (on Thursday) night serving their community.
"Fortunately they are left simply shaken by what happened last night, but we are treating this incident as a credible attempt to murder those officers."
He added: "We have seen evidence of what we believe is a viable explosive device.
"Fortunately, the officers have not been injured in this attack, but this attack took place in a busy residential area, it was absolutely reckless and any member of the public, never mind our police officers, could have been seriously injured."
Asked who could be responsible, the officer said: "Given the location of the attack and previous incidents, a strong line of inquiry would be the New IRA."
Mr Singleton said PSNI Chief Constable Simon Byrne had met local officers in Strabane to offer his support.
Sinn Féin vice president Michelle O'Neill said any attempt to kill officers was "reprehensible".
She tweeted: "Those involved in this attack will not succeed in dragging society backwards.
"We must all unite against these reckless actions. We must keep building the peace and moving forward."
Any attempt to attack or kill police officer's is reprehensible. Those involved in this attack will not succeed in dragging society backwards. We must all unite against these reckless actions. We must keep building the peace and moving forward.— Michelle O’Neill (@moneillsf) November 18, 2022
DUP leader Jeffrey Donaldson said: "This callous and seemingly pre-meditated attack must be roundly condemned.
"Attempts on the life of police officers were wrong in the past and remain wrong today. There is always an alternative to violence.
"Northern Ireland will not be held to ransom by fringe elements intent only on bloodshed and dragging our society backwards.
Taosieach Michéal Martin was in Newry, Co Down, when news of the attack began to emerge.
He said: "I have just been hearing news overnight and we do need further clarity in terms of what happened here and I understand an investigation is under way.
"But any such attempt to injure members of the security forces or the PSNI would be absolutely shocking and stands to be condemned.
"It is quite shocking, if that is the case, that something like that would happen."
The Police Federation for Northern Ireland (PFNI) said the attack in Strabane was a "desperate, reckless act to murder officers working for the entire community".
PFNI chair Liam Kelly said: "The terrorist goal was to cause heartache and misery and return Northern Ireland to the dark ages.
"We are grateful that officers in the vehicle targeted by these cowards were unhurt.
"The attackers wanted their roadside device to cause maximum damage and we are thankful they failed in their objective.
"Nothing is gained by such a callous, hate-filled incident. The terrorist threat is rated 'substantial' and I would appeal to all officers to step up their vigilance.
"This attack is a reminder to us all that terrorists are still active in our community."