The brother of Manchester Arena suicide bomber Salman Abedi went on trial in London on Tuesday, accused of helping him plot the attack that killed 22 people at an Ariana Grande concert.

Britain police have released CCTV footage of Manchester bomber Salman Abedi on the night of the attack as thousands defied the terror threat to take part in the Great Manchester Run on Sunday.

A total of 10 people are in detention in Britain and Libya over Monday's suicide bombing on a pop concert in the northwestern English city of Manchester by a British-born man of Libyan origin.

Russian authorities on Friday warned its citizens against visiting Britain after London raised its threat level in the wake of the Manchester suicide attack.

Suspected Manchester suicide bomber Salman Abedi had expressed a desire to avenge the killing of a friend in the British city last year, a source close to his family said Thursday.

The father of suspected Manchester suicide bomber Salman Abedi was once part of a Libyan militant group with alleged ties to Al-Qaeda, a Libyan security source said Thursday.

The attack on a Manchester pop concert that killed 22 people was "likely" the work of more than one person, British interior minister Amber Rudd said Wednesday.

British police on Tuesday named the suspected attacker behind the Manchester concert bombing that killed 22 people as Salman Abedi, but declined to give any further details.