Manchester Arena bomb-plotter Hashem Abedi is being held at County Durham’s maximum-security Frankland Prison, a court has heard.

The prison is one of three with separation centres, dubbed “jails within jails”, which were first announced in 2017 to tackle extremism behind bars.

Abedi, 23, was found guilty by a jury in March of 22 counts of murder, attempted murder and plotting to cause an explosion likely to endanger life.

His older brother, Salman Abedi, who was 22, detonated the suicide bomb in the foyer of Manchester Arena at 10.31pm on May 22 2017, as thousands of men, women and children left a concert by pop star Ariana Grande.

Abedi was handed a record-length sentence in August for his role in the attack, which killed 22 people and injured hundreds of others.

He could die behind bars after being handed 24 life sentences with a minimum term of 55 years before he can be considered for parole.

It emerged during a hearing at the Old Bailey on Thursday he is being held at Frankland Prison, which has housed other notorious inmates, including Fusilier Lee Rigby’s terrorist killer Michael Adebolajo, Yorkshire Ripper Peter Sutcliffe, and Charles Bronson.

The trial judge, Mr Justice Jeremy Baker, confirmed that Abedi will be subject to a 30-year notification order if he is ever freed, following a prosecution oversight during the original sentencing hearing.

The judge said the prison authorities at HMP Frankland had offered Abedi the chance to provide a response ahead of the hearing.

“Mr Abedi made it clear that he didn’t wish to do so and confirmed that he didn’t request to be present at this hearing,” he added.

It is not known whether Abedi is being held in the jail’s separation centre – the only one currently in use in England and Wales, although Full Sutton and Woodhill also have them available.

Inmates can be moved to the specialist units if they are linked to terror plotting or considered to pose a risk to national security.

The Abedi brothers, from Fallowfield in south Manchester, spent months ordering, stockpiling and transporting the deadly materials for the terror attack, using multiple mobile phones, addresses and runaround vehicles to make their bomb.

They joined their parents in Libya the month before the blast, but Salman returned to the UK on May 18.

He bought the final components needed for the bomb, rented a flat in the city centre in which to build it, and carried out reconnaissance on the arena before finally executing the plot – the final moments of which were caught on CCTV.

The 22 people who were killed were: off-duty police officer Elaine McIver, 43; Saffie Roussos, eight; Sorrell Leczkowski, 14; Eilidh MacLeod, 14; Nell Jones, 14; Olivia Campbell-Hardy, 15; Megan Hurley, 15; Georgina Callander, 18; Chloe Rutherford, 17; Liam Curry, 19; Courtney Boyle, 19; Philip Tron, 32; John Atkinson, 28; Martyn Hett, 29; Kelly Brewster, 32; Angelika Klis, 39; Marcin Klis, 42; Michelle Kiss, 45; Alison Howe, 44; Lisa Lees, 43; Wendy Fawell, 50; and Jane Tweddle, 51.

British police said they had arrested two men on Saturday as they stepped up their efforts to capture a suspected network behind the suicide bomber who killed 22 people in Manchester earlier this week.

Officers used a controlled explosion to gain entry to the address in the north of the city where the latest arrests were made. Detectives are now questioning 11 men over the attack by Salman Abedi at a pop concert in Manchester on Monday.

Some hours later, police cordoned off a large area in the Moss Side area of south Manchester and houses were evacuated with a bomb disposal unit sent to the scene.

A man working in a local shop, who declined to be named, told Reuters he saw three men being taken away from the address.

“As part of an ongoing search at a property in Moss Side an evacuation is currently being carried in the area,” police said in a statement.

While Britain’s most senior counter-terrorism officer said police were confident that they had made “immense” progress and had apprehended a “large part of the network”, extra armed officers will be on duty across the country with security stepped up at some 1,300 events over the long holiday weekend.

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.

The Times newspaper reported on Saturday that intelligence officers had identified 23,000 jihahist extremists living in Britain.

Earlier this week a source with knowledge of the matter told Reuters the security services were managing 500 active operations involving some 3,000 people who were thought to pose a threat.

However, Assistant Commissioner Mark Rowley, the UK police chief for counter-terrorism, advised people to be vigilant but to “go out as you planned and enjoy yourselves”.

There are a number of high-profile events over the weekend including soccer cup finals in London and Glasgow, and the Great Manchester Run.

While police and politicians have praised communities in Manchester for their reaction to the bombing, Greater Manchester Police Chief Constable said there had been a rise in reported hate crimes, from an average of 28 to 56 incidents on Wednesday.

“We can’t directly link these to the events of Monday night and are continuing to monitor the situation,” he said.

Political campaigning for the June 8 national election which was suspended after the Manchester attack resumed on Friday with the bombing becoming a central feature.

The opposition Labour Party, emboldened by a rise in opinion polls, argued that Britain’s foreign policy had increased the risk of attacks and criticised Conservative Prime Minister Theresa May for cutting spending on policing.

May said Labour leader Jeremy Corbyn was saying Britain was to blame for the bombing.

“I want to make one thing very clear to Jeremy Corbyn and to you, and it is that there can never, ever be an excuse for terrorism,” she said at a summit of Group of Seven leaders in Sicily.

A poll on Thursday put May’s Conservatives five points ahead of Labour suggesting a far tighter race than previously anticipated.