LONDON (AP) — Britain's interior minister says the hunt is still on for suspects in the Manchester bombing, and members of attacker Salman Abedi's network may still be at large.

Home Secretary Amber Rudd says that "the operation is still at full tilt" and "we can't be entirely sure that it's closed."

Abedi, a 22-year-old Briton of Libyan descent, killed 22 people on May 22 at an Ariana Grande concert. Police have 11 suspects in custody and have searched properties across the northwest England city.

On Saturday, Britain lowered its official terrorism threat level from "critical" to "severe" after police said they had dismantled a large part of Abedi's network.

Police have released surveillance-camera images of Abedi on the night of the attack and appealed for more information about his final days.