Police have made their 15th arrest in connection with the Manchester bombing following a raid on Sunday (28 May).
A 25-year-old man was picked up in the Old Trafford area of the city and a 19-year-old was detained in Gorton. Both have been arrested on suspicion of terror offences.
Earlier on Sunday (28 May) in nearby Moss Side, residents said they heard a loud band in what was believed to be a controlled explosion.
While the country's threat level is now critical, lowered from severe, Home Secretary, Amber Rudd, said there was no certainty as to whether the terror network of the 22-year-old attacker, Salman Abedi, had been dismantled or whether other bombers were still at large.
She also said that temporary exclusion orders, which ban suspected jihadis from coming back to the UK, had been used.
"The intelligence services are still collecting information about him and about the people around him. But I would not rush to conclusions, as you seem to be, that they have somehow missed something," she said.
She said that there would be an investigation into the possible missed alerts on Abedi, after it emerged that the FBI had warned British intelligence services that he was part of a North African terror cell in Manchester.
A source told the Mail on Sunday that Abedi was believed to be targeting a political figure, claims that MI5 was looking into.
"But nothing came of this investigation and, tragically, he slipped down the pecking order of targets," the source said.
Rudd told the BBC that the operation uncovering Abedi's terror network was "at full tilt".
"Of course people will want to look afterwards to see whether there are signals that could have been learnt, how could we do this better," she said.
Two of those arrested have been released, but 12 people remain in custody.
The grieving parents of Manchester bombing victim Georgina Callander have said the UK government must "open its eyes" on the root causes of terrorism or more parents will lose their children to terror attacks.