A man has been arrested in connection with the Manchester Arena terror attack.
The 19-year-old man was arrested at Liverpool John Lennon Airport on Friday on suspicion of offences contrary to the Terrorism Act and remains in custody, Greater Manchester Police said.
A property on Thelwall Avenue in Fallowfield is being searched as part of the investigation.
Police said, as it stands, 23 people have been arrested in connection with the investigation, of which two were quickly de-arrested, and 20 were released without charge.
Anti-terror officers have already said police suspect suicide bomber Salman Abedi did not act alone and detectives want to speak to his brother in Libya.
Detective Chief Superintendent Russ Jackson, head of the North West Counter Terrorism Unit (NWCTU), said on Thursday that while detectives do not now think Abedi was part of a large network, they do suspect the involvement of others in the attack which had been planned for months.
He said officers were "engaged" with the authorities in war-torn Libya where Abedi's brother, Hashem, is currently being held.
Mr Jackson said: "We don't have evidence of a large network. We do however suspect others were either aware or complicit in the knowledge of this attack."
And he did not rule out further arrests.
Abedi killed 22 people when he detonated a bomb in the foyer of Manchester Arena at the end of an Ariane Grande concert on May 22.
At the home of the man under arrest police forensics teams were taking photos of the inside and the contents of the bins outside the house, a housing association property on Thelwall Avenue, Fallowfield, south Manchester.
A young man and a woman, covering their faces, were led away by plain clothes detectives and taken away in an unmarked car.
A number of locals claimed the family were related to Salman Abedi, which could not be verified.
Abedi's last known address, on Elsmore Road, is on a street around 100 yards away.
Neighbours said a Libyan family have lived at the address for a number of years - a mother, two sons and a daughter, though the father is believed to be in Libya.
Ali Mohamed, visiting a friend at a house across the road, said: "I saw Salman Abedi here. He didn't show any danger or anything bad. He just seemed like a normal kid."
It is understood the 19-year-old arrested was on an inbound flight to the UK when he was held at Liverpool Airport.