London mayor Boris Johnson has given his backing to a police road safety operation as figures revealed a drop in the numbers of cyclists killed or seriously injured in 2013 compared to the previous year.

The figures show there were 475 serious injuries to cyclists in 2013, compared with 657 in 2012 - a 28 per cent fall that means cyclists are killed or seriously injured (KSI) in around one in every 433,000 journeys undertaken in London.

This is the second-lowest rate ever recorded, behind figures for 2006, when there was one KSI for every 434,000 journeys by bike. The fall is partly the result of 'Operation Safeway', which ran in November and December.

Mr Johnson said: "Whilst these new figures are encouraging and a real move in the right direction one death or serious injury is one too many."

He said small-scale safety operations are to be mounted across the capital for two days every month and these are to run indefinitely.

The mayor also announced a number of other measures he is taking to improve cyclists' safety, including building new, protected cycle routes and better junctions.