Manchester Arena bombing: MI5 says it is 'revolted' by 'disgusting' suicide attack

Agency head confirms it is working with police on investigation

MI5 said 'our hearts go out to the families of the victims' (AFP/Getty Images)

The head of the MI5 has condemned the “disgusting” explosion at an Ariana Grande concert in Manchester that killed 22 people.

In a rare statement, Andrew Parker said everyone at the intelligence agency thought the deadly explosion was “revolting” and had been affected by it.

The agency also confirmed it was working to assist the police in its investigation.

“Everyone at MI5 is revolted by the disgusting terrorist attack in Manchester last night. Our hearts go out to the families of the victims, the injured and everyone affected by it,” the statement read.

“Our teams have been working with the police through the night to assist the investigation.

“We remain relentlessly focused, in numerous current operations, on doing all we can to combat the scourge of terrorism and keep the country safe.”

Security experts said the attacker was a single man who detonated a bomb at an exit between the stadium and Victoria Station as the crowds were leaving.

Prime Minister Theresa May said the attacker "deliberately chose the time and place to cause maximum carnage and to kill and injure indiscriminately”.

“The police and security services believe the attack was carried out by one man,” she said on the steps of 10 Downing Street.

“But they now need to whether he was acting alone, or was part of a wider group. It will take some time to establish these facts, and the investigation will continue. The police and security services will be given all the resources they need to complete that task.”

Isis has claimed responsibility for the attack, but police have not confirmed the background of the attacker or if he had any links to Isis.

He triggered the improvised explosive device around 10pm, killing 22 people and injuring 59. More than a dozen children were immediately taken to the same hospital.

Questions remain as to how he acquired the explosives, which would take training to assemble and detonate, how he selected his target and whether he had obtained ID to access a vulnerable area close to the arena.

Officials say it is the largest and deadliest attack in 12 years, since more than 50 people died in the London tube and bus bombings in 2005.

The latest blast has also shown an area of expertise compared to recent attacks, such as at Westminster in March, where the attacker used his car and a knife to plough into passers-by on the pavement and stab a police officer.