POLICE presence at today's London Marathon has been increased in the wake of the atrocities in Boston.
The annual 26.2 mile race around the capital starts this morning (Sunday, April 21) in Blackheath, South East London.
Chief Superintendent Julia Pendry revealed on Friday that several hundred additional police officers have been drafted in to help patrol the event.
The 37,000 participants in London are expected to show solidarity with those affected by the Massachusetts attack.
There will a 30-second period of silence before the start - and runners are being encouraged to wear black ribbons.
Virgin London Marathon has pledged to donate £2 for every finisher in today's event to The One Fund Boston - set up to raise money for the victims of the explosions.
Members of the public coming to the capital are being asked to make sure that they keep their belongings with them to avoid triggering security alerts.