A man has been arrested at Birmingham Airport in connection with the 1996 IRA bombing in Manchester, police have said.
Although no one was killed in the explosion, around 250 people were injured in what was described as the UK mainland's largest bomb since World War Two.
The man was arrested at Birmingham Airport on Thursday night on suspicion of terrorism offences, Greater Manchester Police confirmed. No one has ever been charged over the attack that took place on 15 June 1996.
The city centre was packed with thousands of shoppers and football fans ahead of a Euro 96 match later that day between Scotland and England at Wembley Stadium.
Police evacuated the area after being alerted by telephone of a bomb threat.
The explosives were in a lorry that was parked on Corporation Street and detonated soon after, causing a huge mushroom cloud that rose above the city.
Greater Manchester Police said it was "determined to hold those responsible for this attack to account regardless of the time passed".
The suspect, who is in police custody, will be interviewed by Counter Terrorism police officers.
Detective Superintendent Andrew Meeks, Head of Investigations, said officers had been "reinvestigating for several years.
"Although thankfully no one was killed during the 1996 Manchester bombing by the IRA, hundreds of people were left with injuries - many of which were life-changing. "Many more across Greater Manchester and the North West were affected by what happened on that day."
He added that police had "always been committed to holding those responsible for the attack to account." He said there was "a team of dedicated detectives re-examining the original case files and pursuing new lines of inquiry."