A fifth man has been arrested in connection with the attempted murder of an off-duty police officer in Northern Ireland on Wednesday.

Detective Chief Inspector John Caldwell was shot and seriously injured in front of his young son and others after a coaching session at a sports complex in Co Tyrone.

According to police, the attack happened while the detective was loading footballs into the boot of his car when the two men opened fire.

The man, aged 43, was arrested in the Stewartstown area of Co Tyrone on Friday and is currently being questioned by detectives.

Four other men - aged 22, 38, 45 and 47 - also arrested in connection with the attempted murder remain in police custody.

Assistant Chief Constable Mark McEwan earlier said: "Following the attempted murder of Detective Chief Inspector John Caldwell on Wednesday... I can confirm that we are now treating it as terrorist-related and our primary line of enquiry is the New IRA".

PSNI Chief Constable Simon Byrne has said that Detective Caldwell remained "critically ill and heavily sedated" in hospital following the attempt made on his life.

Detectives want anyone who was in the area or who witnessed what happened to contact them.

(Left to right) SDLP leader Colum Eastwood, DUP leader Jeffrey Donaldson, PSNI Chief Constable Simon Byrne, Sinn Fein deputy leader Michelle O'Neill, UUP leader Doug Beattie, and Alliance party member Stephen Farry speaking to the media outside PSNI HQ in Belfast, Northern Ireland. Picture by: PA Images / Alamy Stock Photo

Earlier, Sinn Fein's Michelle O'Neill said all communities in Northern Ireland "stand united as one voice in condemnation" of the attack.

"It is so important in moments like this that we stand united," she said.

"And we do stand here united as one voice in our condemnation against this horrific attack on a police officer, someone who is part of our community."

She added: "I think the most powerful message we can send is to stand with the chief constable today and to stand with the police service and to say 'this is not good enough'.

"This is an attack on all of us, this is an attack on our community".

Ms O'Neill was speaking while standing alongside the head of the PSNI and political representatives from the five main Stormont parties - including DUP leader, Jeffrey Donaldson.

Main image: PSNI officers at the scene of the shooting of Detective Chief Inspector John Caldwell in Omagh, Co Tyrone. Picture by: PA Images / Alamy Stock Photo