Russ Jackson, head of counterterrorism policing for northwest England, said today that police may make more arrests in the investigation.
Salman Abedi, a Briton of Libyan heritage, detonated a knapsack bomb as crowds were leaving Manchester Arena on May 22, killing 22 people and himself.
In the days after the attack, police arrested 22 people on suspicion of terrorism offenses and said they had rounded up a large part of Abedi's network. But all the suspects were subsequently released without charge.