Members of the network used by Manchester bomber Salman Abedi may still be at large, Britain’s interior minister said, as the terrorism threat level in the country was lowered due to significant progress in the investigation.
Police say that 1,000 people are working on the investigation, trying to track down Abedi's accomplices and piece together his movements in the days before the suspected suicide attack, which killed 22 people at a concert hall on May 22.
Authorities say they have arrested a large part of the network behind the bombing as police continue to close in on the group.
Asked during a BBC interview on May 28 whether some of the group members were still at large, Home Secretary Amber Rudd said: “Potentially. It is an ongoing operation.”
Police say they have 11 people in custody, including Abedi’s elder brother, Ismail. Another brother and Abedi's father have been detained in Libya.
On May 27, Britain lowered its official terrorism threat level from its highest rating "critical," meaning an attack could be imminent, to "severe."
Security remains high at major events across Britain on May 28, including the Great Manchester Run road race, where police armed with submachine guns protected participants and spectators.
Rudd said that intelligence agencies were monitoring 3,000 suspected extremists and had a wider pool of 20,000 people of interest.