Man arrested in connection with Manchester Arena bomb after raid
One man was arrested in the Moss Side area of Manchester in the early hours of Friday morning and detectives searched a property in St Helens.
Eight men are now in custody in connection with Monday's atrocity, with police and security agencies working at pace amid fears of further attacks.
A spokesman for GMP said: "The arrest is connected to Monday’s attack on the Manchester Arena, but this is a fast moving investigation and we are keeping an open mind at this stage.
"As it stands ten people in total have been arrested in connection with the investigation, of which a man and a woman have since been released without charge.
"Eight men remain in custody for questioning."
The developments followed a fraught day in which Greater Manchester Police severed intelligence-sharing ties with the US due to evidence being repeatedly passed to journalists without permission.
"While we do not usually comment on information-sharing arrangements with international law enforcement organisations, we want to emphasise that, having received fresh assurances, we are now working closely with our key partners around the world including all those in the Five Eyes intelligence alliance," Mr Rowley said.
Abedi, who was known to security services for his radical views, was said to have been in close contact with family members moments before slaughtering concert-goers on Monday.
A relative of the 22-year-old said he had felt increasing frustration at his treatment in the UK, heightened after a friend was fatally knifed in what he perceived to be a religious hate crime.
She added that the British-born bomber began referring to others in the country as "infidels" who were "unjust to Arabs".
Libyan authorities, who are questioning Abedi's parents and siblings, claimed he made a final phone call to his mother on the eve of the attack, in which he said: "Forgive me."
Music fans were targeted at an Ariana Grande concert at Manchester Arena in the worst terrorist attack on British soil since the July 7 bombing in London in 2005.