A total of 10 people were arrested, but a 16-year-old boy and 34-year-old woman were released without being charged.
United Kingdom broadcaster Sky News aired two screengrabs of security camera footage, reporting that British police believed they showed Abedi walking in Manchester's Arndale shopping centre late on Friday.
It comes as fresh fears were raised he may have made a second bomb, after raids on his home reportedly uncovered a stash of chemical explosives.
In Libya, Abedi's brother - identified as 20-year-old Hashim Ramadan Abu Qassem al-Abedi - was arrested Tuesday night on suspicion of links to ISIS, said a statement from a Tripoli militia known as the Special Deterrence Force.
Greater Manchester Police told Metro.co.uk: 'This morning (Friday 26 May 2017) we have arrested a man in the Moss Side area. "He was shocked and panicked when he saw the news", said Mohammed El-Haduri, the manager of St Helens Pizza.
"I'll be returning to the incredibly courageous city of Manchester to spend time with my fans and to have a benefit concert in honor of and to raise money for the victims and their families".
With British police investigating an alleged network linked to the British-born suicide bomber, Salman Abedi, the matter of information leaked to USA media will be taken up by British Prime Minister Theresa May when she meets President Donald Trump at a later North Atlantic Treaty Organisation summit, the BBC reported. Army and armed police officers patrolled major sites across the country.
In the note, Grande also praised her fans for their response to the incident, which left 22 people dead and more than 60 injured, including several children and teens.
The latest revelations come as intelligence sharing between the USA and the United Kingdom resumed after a temporary halt following a series of high-profile leaks to US media of details surrounding the Manchester bombing investigation, which were blamed on USA government officials.
"However, it is important that we continue with these searches", Hopkins said".
Meanwhile, national level campaigning for the June 8 general election is set to resume today after local level campaigns resumed yesterday following suspension in the wake of the attack.
However assistant commissioner Mark Rowley added that there are likely to be more arrests over the next few weeks.
"We must be courageous enough to admit that the "war on terror" is simply not working".