Four failed rucksack bombers hunted by police

Four suspected suicide bombers are being hunted tonight after police recovered viable explosive devices following today’s attempted bomb attack on the London transport network.

The four devices, which were all contained in rucksacks, were found at each of the four sites of the attempted explosions.

Detectives believe at least four bombers were involved in the failed attack and they are understood to be still at large. It is thought that police received reports of people running away from two of the attempted blast sites.

No-one has been arrested directly in connection with the blasts. Two earlier arrests are not believed to be linked.

A man was arrested today in Tottenham Court Road but police sources said it was not clear whether he was linked to the failed attacks. He is not believed to have been arrested under anti-terror laws.

Another man was arrested earlier at Downing Street but is not thought to be directly linked to the attempted bombings. Both are still in custody, police said.

Three of the four devices are thought to be of a similar size and weight to the bombs used in the July 7 attacks in the capital. The fourth was smaller and appears to have been contained in a small plastic box.

It is understood that an initial examination of the devices has shown that they contained constituents which appear similar to the explosives found in a bath at a property in West Yorkshire.

Police believe they represent a serious attempt to detonate explosives on the London transport network in a similar way to the bombing two weeks ago.

Metropolitan Police Commissioner Sir Ian Blair said earlier that the intention of those who tried to set off the devices “must have been to kill”.

It is believed that on three of the devices the detonators went off but the bomb failed to explode. On the fourth it is thought that the detonator itself failed.

Forensic experts are now thought to be examining the devices and trying to establish whether there is a link between them and the explosives found in West Yorkshire in the wake of the London suicide bombings.

No-one was seriously hurt in today’s incidents.