Britain's terror threat level was on Saturday reduced to "severe" from "critical" after a "significant amount of police activity" led to the arrest of 11 suspects linked to the suicide bombing at a concert in Manchester.
The terror threat level now indicates that an attack remains highly likely rather than imminent. The Army troops deployed as a result of Operation Temperer will be reduced from Monday night.
Prime Minister Theresa May made this announcement after leading a meeting of the government's emergency committee Cobra on Saturday morning.
She said "significant activity" by the police during the last 24 hours led to the threat being reduced.
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."
It had been set at "critical" in the aftermath of the bombing in Manchester.
Earlier, a new arrest on Saturday morning has taken the total number of men being held in custody over the suicide bombing in Manchester to 11. Greater Manchester Police had arrested another man overnight on suspicion of terrorism offences as part of its ongoing investigation into the attack on Manchester Arena on Monday that claimed 22 lives. "As part of the ongoing investigation into the attack on Manchester Arena, two men aged 22 and 20 have been arrested on suspicion of offences contrary to the terrorism act," a Greater Manchester Police statement said.
"As it stands, 13 people in total have been arrested in connection with the investigation, of which two people have since been released without charge. A total of 11 men remain in custody for questioning," the statement said. The arrests were made after searches in Cheetham Hill area of Manchester, where a controlled explosion was used to gain entry into an address.
Greater Manchester Police had arrested another man overnight on suspicion of terrorism offences as part of its ongoing investigation into the attack. The cousins of the bomber are believed to be among those arrested. A 34-year-old woman and 16-year-old boy who were also arrested have been released without charge. Investigators believe 22-year-old Manchester-born suicide bomber Salman Abedi, from a family of Libyan origin, acted as part of a terrorist network and their focus had been on intercepting his wider network.