A cousin of Manchester bomber Salman Abedi posted antisemitic tweets appearing to celebrate the holocaust, it has emerged.

Abderahman Forjani, 21, who was arrested along with his 24-year-old brother Abdalla as part of the investigation into the bombing, posted: 'If only Hitler was still alive - these Jews would be burned in gas chambers.'

He also posted that Manchester is his 'number 1 enemy' and a 's***hole', as well as declaring that he wanted Britain to go bankrupt, according to The Times.

His account has since been deleted.

A cousin of Manchester bomber Salman Abedi (pictured) posted antisemitic tweets appearing to celebrate the holocaust, it has emerged

The revelation comes as police rounded up ‘a large part’ of the suspected Libyan terror cell.

Officers said they had arrested the ‘key players’ in the Middle England gang of alleged jihadis who helped Salman Abedi, 22, wreak horror in Manchester.

University students Mohamed and Yahya Werfalli were arrested in the early hours of Saturday - hours before Theresa May lowered the UK’s terror threat level from critical to severe.

The brothers, who like other suspects are British born but of Libyan heritage, are believed to move in the same friendship circles as the Manchester bomber Salman Abedi, also 22.

Yahya is listed on Facebook as a friend of the bomber’s brother, Hashem, 20.

There are now 14 people in UK custody, in addition to Ramadan and Hashem Abedi, Salman's father and younger brother respectively, who are being held in Libya.

University students Mohamed (left) and Yahya Werfalli were arrested in the early hours of Saturday - hours before Theresa May lowered the UK’s terror threat level from critical to severe

A further two were arrested in Britain and released without charge.

A 23-year-old man was arrested by police yesterday over the Manchester bombing in Shoreham-by-Sea, West Sussex, 263 miles away from the scene of the terror attack.

Earlier in the day a 19-year-old was detained in the Gorton area of Manchester on suspicion of terror offences, while a 25-year-old man was arrested in Old Trafford.

Controlled explosions were also carried out in Moss Side.

A neighbour told MailOnline: 'We were in the kitchen cooking the Sunday meal and I heard a loud bang.

'I looked out the front door and there were armed police and the army in the front and back garden.

'It was really loud. I thought it was a bomb but I believe it was a flash grenade. It was so loud that to be honest it sounded like a bomb.'