Detectives have arrested the chief executive of a Libyan marketplace website and raided more houses in an effort to close in on the Manchester Arena bomber’s network.
A 23-year-old man – understood to be Ala Zakry, who runs Hasoub Alafak, a UK-registered online marketplace based in Tripoli – was arrested in the Sussex town of Shoreham-by-Sea, about 265 miles away from the scene of last week’s attack.
Houses in Whalley Range in Greater Manchester and Chester in Cheshire were searched overnight by counter-terrorism detectives.
Police officers are also searching a landfill site in Pilsworth, near Bury.
Fourteen men remain in custody.
A week has passed since Salman Abedi detonated a backpack bomb in one of the entrances to the Manchester Arena, killing 22 people and injuring dozens of others at the end of a concert by American pop singer Ariana Grande.
Greater Manchester police said on Monday that a 23-year-old man in Shoreham-by-Sea had been arrested on suspicion of offences contrary to the Terrorism Act.
Police officers stood guard outside Zakry’s flat in Brunswick Road, which is above two shops, a clothing boutique and a hairdresser, in the seaside town.
Zakry is also a digital marketing specialist and a trainee pilot, according to his social media profile.
The Hasoub Alafak website also offers international electronic funds and internet payment services.
A colleague in Tripoli said she had spoken to Zakry on Sunday but could not contact him on Monday. She said his family lived in Libya, although he had an aunt in the UK.
The company mainly serves Libyan customers and its work involves purchasing products from websites such as Amazon and importing them to Libya for customers.
Zakry’s mother, Dr Amal Azzuz, told the Guardian her son was a “good boy” and would never be involved with terrorism.
“We are very sorry about what happened in Manchester; we’ve no words for how bad it was,” she said.
“But this is how I know Ala could have nothing to do with this.
He has no relation to this kind of behaviour.”
Violet Mainda, who owns the hairdresser beneath Zakry’s flat, said she would be “shocked” if Zakry was connected to the Manchester bombing.
“He is a very nice boy,” she said.
Meanwhile, a police sniffer dog has been sent into a terraced house in Banff Road, off Wilmslow Road in the Rusholme area of Manchester, where police said earlier they knew Abedi had spent time in the run-up to the arena attack.
Natalie Langford, a PhD student, said she saw four men being taken away by police shortly after 5pm on Monday.
The first two were bundled into a marked police van and the third and fourth into two unmarked cars, she said.
Greater Manchester police confirmed a search was ongoing in Rusholme but no arrests had been made.
MI5 has launched two urgent inquiries into how it missed the danger posed by Abedi amid claims his interest in being a potential terrorist killer was repeatedly reported to the authorities.
Britain’s domestic security service started one review last week, which will aim to quickly identify any glaring errors, while the other will be more in-depth, the Guardian learned.
Abedi is understood to have been on a list of 20,000 individuals said to have been considered “subjects of interest” to security services in the past, but not among 3,000 suspects subjected to about 500 ongoing investigations.
The former Liberal Democrat leader Menzies Campbell said there should be an independent parliamentary inquiry into the alleged missed opportunities to intercept Abedi.
Campbell was a member of the intelligence and security committee when it published a 2014 report into the intelligence services’ handling of information about the two people who went on to murder the soldier, Lee Rigby, in May 2013.
Campbell said: “The ISC has the right to determine its own programme.
I would be astonished if the new committee, particularly if Dominic Grieve [who was the chair when parliament dissolved for election] is the chair, would not instigate an inquiry into the circumstances around the Manchester atrocity.
“There will be problems with an inquiry until the criminal proceedings are completed, if there are any.
It could be held in private, with the conclusions published when criminal proceedings have ended.”
Six children are among 19 people in critical care following the attack, NHS England said.
The children are among 12 receiving treatment at the Royal Manchester children’s hospital.
Critical care means patients may be receiving help breathing or organ support but does not necessarily mean they are in a critical condition.
Fifty-two people are in hospitals around Greater Manchester, down from 116 immediately after the attack.
There are signs Manchester was returning to normal as it was announced that Manchester Victoria station, which has been shut since the attack on 22 May, will reopen from Tuesday with Northern, TransPennine Express and Metrolink operating a full timetable of services.
The mayor of Greater Manchester, Andy Burnham, said: “We continue to grieve with the families of those who died and support those injured.
I’ve been clear that all public bodies must take a families-first approach in the days, months and years ahead to ensure their needs and wishes are fully understood and considered.
“Victoria station’s reopening is an important statement about our city’s recovery from this devastating attack.
It continues to send out the message that we will not be bowed, we will not be divided and we will stand together.”