The UK's terror threat level has been reduced as police unravel the bomb-making methods of the Manchester suicide attacker and close in on suspected co-conspirators.
Detectives were said to have a "greater understanding" of the way Salman Abedi built the device which detonated in a crowd of concert-goers on Monday.
A wave of arrests and raids are believed to have closed the net on the terror ring behind the attack, but counter-terror chief Mark Rowley warned "more arrests and more searches" could follow.
Prime Minister Theresa May announced on Saturday that troops will gradually be withdrawn from the streets from Monday onwards, having been drafted in to bolster police numbers.
The de-escalation in the country's threat level from its highest point suggests confidence that the operations conducted in the last week have stifled any imminent threats.
Currently 11 people remain in police custody after a raid on an address in the Cheetham Hill area of Manchester saw a 20-year-old and a 22-year-old detained on suspicion of terror offences.
It came amid searches at a separate property in Cheetham Hill and an address in the Longsight area in south Manchester, while a road in Moss Side was evacuated by officers searching a home there.
Mr Rowley, the country's leading anti-terror officer, said: "We are getting a greater understanding of the preparation of the bomb.
"There is still much more to do - there will be more arrests, there will be more searches.
"But the greater clarity and progress has led (Joint Terrorism Analysis Centre), the independent body which assesses threat, to the judgment that an attack is no longer imminent."
Monday night's massacre at the Manchester Arena left 22 dead, including seven children, and scores of others injured - the worst terrorist outrage to hit Britain since the July 7 attacks in 2005.
It led the JTAC to increase the terror threat level to "critical", meaning a further terror attack was considered "imminent".
It has now been reduced to "severe", meaning an attack is "highly likely".
Speaking after a meeting of the Government's Cobra emergency committee, Mrs May said the decision had been taken after "a significant amount of police activity" over the last 24 hours.
She said: "The public should be clear about what this means - a threat level of severe means an attack is highly likely. The country should remain vigilant."
The terror threat had been at critical for the first time in a decade.
Greater Manchester Police Chief Constable Ian Hopkins hailed "significant progress" in the investigation, following disclosures that "key players" allegedly connected to the attack had been arrested.
Mrs May also said Operation Temperer, allowing the military to be deployed to protect key sites, will be rolled back after the bank holiday.
She said: "To provide maximum reassurance to the public Operation Temperer will continue to operate until the bank holiday concludes.
"Then, from midnight on Monday onwards, there will be a well-planned and gradual withdrawal of members of the armed forces, who will return to normal duties."
A huge bank holiday weekend security operation is under way as tens of thousands of people attend major spectacles including the FA Cup Final at Wembley and the Premiership Rugby Final at Twickenham.
Arrangements have been reviewed at more than 1,300 events, while the pool of armed officers available to be deployed around the country has been boosted by 1,100 after military personnel were drafted in to cover guard posts at key sites.
Responding to the reduction of the terror threat level from critical to severe, Labour leader Jeremy Corbyn said: "I would like to thank the army, police and security services who have worked extremely hard to keep us safe after the horrific terror attack on Monday. It is a testament to their efforts that the threat level has been reduced.
"The British people have shown themselves at their best this week, the outpouring of solidarity and compassion is what defines our country."