Counter-terrorism police in Manchester have arrested a man in the Moss Side area of the city.
They said the arrest, in the early hours of Friday morning, is connected to Monday's terrorist attack at the Manchester Arena in which 22 people were killed.
A short time later, Greater Manchester Police confirmed they have searched an address in the St Helens area of Merseyside - also in relation to Monday's attack.
In total, they have arrested 10 people in connection with the investigation, of which a man and a woman have since been released without charge.
Eight men remain in police custody.