On Sunday, police carried out searches in Manchester's Moss Side and the Old Trafford area, where a 25-year-old man was arrested. Police are searching a number of properties and have 11 suspects in custody in connection with Monday's explosion at an Ariana Grande concert in Manchester, which killed more than 20 people and injured dozens.
Greater Manchester Police said two men, aged 20 and 22, were detained early Saturday in the northwest England city on suspicion of terrorism offenses. In addition, Manchester bomber Salman Abedi's father and younger brother are in detention in Libya.
Hopkins and Basu said they had gathered significant information about Abedi, a 22-year-old Briton born to Libyan parents, how his bomb was built, his associates, finances, the places he had been and the wider conspiracy.
As the probe continues, Britain lowered its security threat level Saturday to "severe", Prime Minister Theresa May said.
Britain remains on its highest threat level of critical, meaning an attack is expected imminently, with the army backing up police and hospitals across the country have told staff to be ready for another incident.
A severe threat means an attack is "highly likely", according to the scale set by Britain's Joint Terrorism Analysis Centre.
Her comments come after police issued CCTV images of Abedi in a plea for information about his movements between 18 May and Monday's attack, which left 22 people dead.More news: Kevin Love on Cavaliers: "I don't feel like we're underdogs"
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Armed police were stationed among spectators at the Great Manchester Run as the latest large-scale event took place in the city in the wake of the terror attack.
Ariana Grande posted a letter Friday to Twitter saying she would return to Manchester to perform a benefit concert to raise money for the victims of the bombing and their families. But the deployment of soldiers on the streets in support of police will be phased out starting Monday night, May said.
Armed police will patrol events in Manchester, London and elsewhere this weekend as Britain marks its first holiday since the Manchester bombing. "There will be more arrests and there will be more searches", he said.
When asked how many potential militants the government was anxious about, Rudd said the security services were looking at 500 different potential plots, involving 3,000 people as a "top list", with a further 20,000 beneath that.
There were prayers for the victims at church services across Manchester on Sunday.
"What we are doing is challenging the people who are delivering end-to-end encryption to work with us so that we have a way of keeping people safe", she said. "We won't let hate win".