A young man suspected of throwing a fire extinguisher at police during the Millbank riot has been arrested.

Scotland Yard said the 23-year-old was held by officers in Cambridgeshire on suspicion of violent disorder.

A spokesman said: "This arrest follows an investigation into public disorder where a fire extinguisher was thrown from the roof of Millbank Tower."

Teams of officers from the Met's public order intelligence unit have been scouring footage recorded as protesters stormed the building housing the Tory party headquarters.

Police Federation representatives have called for the person who flung the empty metal fire extinguisher to be charged with attempted murder after it narrowly missed two riot squad officers.

The incident was one of the defining moments of the four-hour stand-off on Wednesday afternoon after a breakaway group of students attacked the Millbank office complex.

Earlier today the Met revealed ten of the 54 people arrested during sprawling outbreaks of disorder were school pupils aged under 18 and the remainder were all students, including 21 women.

Activist websites have published step-by-step instructions to those who fear they may be identified and arrested in the aftermath of the violence.

One anti-police site told participants to destroying potential evidence, including clothing and any distinctive jewellery worn.

A contributor urged demonstrators not to panic or give themselves up as a result of the flood of media coverage.