29 May, 2017
Early on Monday a man, 23, was arrested in Shoreham-by-Sea, West Sussex, on suspicion of terrorism offences.
Police were also searching another address in the south of Manchester.
MI5 has launched a "post incident investigation" into how the Manchester bomber was overlooked, while a separate report is being prepared for ministers and those who oversee the work of the service.
Britain's MI5 has begun an internal review of how it handled intelligence on Manchester suicide bomber Salman Abedi, who was known to the authorities but not under active investigation, a source told Reuters on Monday.
Seven children were among the 22 people who died when Abedi detonated a bomb on 22 May at the end of a concert by United States singer Ariana Grande at Manchester Arena. Two were released by police without charge, while 14 remain in custody.
Abedi was known to British security services before the bombing, the government has said, but Rudd declined to comment on exactly what had been known about him.
Intelligence officials also knew of Abedi's links to a militant Islamist group in Libya - titled the Libyan Islamic Fighting Group (LIFG) - and to Isis-linked jihadists in the United Kingdom, but still took no action to detain the 22-year-old.
Prime Minister Theresa May said developments in the investigation into the bombing meant that intelligence experts had made a decision to lower the threat level from its highest rating "critical", meaning an attack could be imminent, to "severe".
A total of 16 people have been arrested in connection with the attack, in which 22 people died.
CCTV stills of Abedi, bespectacled and casually clothed, were released by police in a plea for information about his movements between May 18 and the attack.
The images show Abedi in the hours before the attack, wearing sneakers, jeans, a dark jacket and a baseball cap. British extremist Salman Abedi detonated a powerful bomb in a suicide attack at a concert by United States singer Ariane Grande.
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 reported.
"I would not rush to conclusions. that they have somehow missed something", Rudd said. "It might be just a question mark about one of them, or something serious with that top list", she said.
