The UK's terror threat level has been reduced as fresh arrests and raids were carried out linked to the Manchester suicide bombing.
Troops will be gradually withdrawn from the streets from Monday onwards, having been drafted in to bolster police numbers, Prime Minister Theresa May said.
The de-escalation suggests confidence that a wave of counter-terror operations against attacker Salman Abedi's suspected network has stifled any imminent threats.
But Mark Rowley, the country's most senior counter-terror officer, said "more arrests and more searches" were likely as the huge investigation continues.
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 Joint Terrorism Analysis Centre (JTAC) to increase the terror threat level to "critical", the highest on the scale, 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 revelations that "key players" allegedly connected to the attack had been arrested.
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 followed 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.
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.