MI5 is to hold an inquiry into the way it dealt with warnings from the public that the Manchester suicide bomber, Salman Abedi, was a potential threat.

The security service, which was alerted to Abedi’s extremist views three times prior to last Monday’s attack, will examine how it dealt with the warnings.

Home Secretary Amber Rudd said it was right for MI5 to review its processes.

Early on Monday a man, 23, was arrested in Shoreham-by-Sea, West Sussex, on suspicion of terrorism offences.

Officers from Greater Manchester Police also began searching a site in Pilsworth near Bury on Monday afternoon.

On Sunday, two men were arrested in Manchester – a 19-year-old man in Gorton and a 25-year-old man in the Old Trafford area.

In all, 14 men are now being questioned in connection with the investigation into the attack.

Searches were also carried out at addresses in the Whalley Range area of Manchester and in Chester on Sunday night.