Bomb was designed to kill as many as possible

A DEVICE packed with nuts and bolts was used to inflict maximum injury in the Arena bomb attack.

The M.E.N. understands from several sources that many of the casualties who survived were left with metal fragments and full bolts embedded in limbs.

One source said: “When casualties arrived at Oldham Royal Hospital all needed to go to theatre, one patient had a leg which was peppered with metal.”

Another source told the M.E.N.: “It is terrible targeting young kids in such a manner. The metal in the bomb becomes shrapnel causing greater loss of life in a confined space like the Arena, than explosives on there own would do.”

“It is like a hand grenade effect or sawn-off shot gun, spreading injury. Each fragment is a weapon in its own right – it is like a hundred bullets coming out at once.”

In March last year nail bombs were used in co-ordinated suicide bombings by Isis during attacks on Brussels Airport, Zaventem and the metro station in Maelbeek. Thirty-two civilians and three terrorists were killed.

The blast that killed 22 people was caused by a ‘dockyard confetti’ explosive device made with household item, one expert believes.

A suicide bomber detonated the homemade device inside the foyer of the Arena.

It is believed the device was made from parts such as screws, nuts and bolts or ball bearings.

Security experts agree that the bomber used a “sophisticated” method of attack.

Chris Phillips, former police office and counter-terrorism expert described the latest attack as “a step up”.

He told BBC Radio 4’s Today programme: “It sounds like this was a strapped-on suicide belt and also from what we just heard, perhaps, with what we call dockyard confetti which is the little bits of nuts and bolts that are attached to the vest. And those unfortunately are there deliberately to kill people and that’s the whole purpose of them.

“This does look like a step up and my worry, and I think the police’s worry now, is that this person probably wasn’t acting alone and there are other people that need to be captured.”