The London Marathon is beginning, the first major international marathon since the bomb attack in Boston.

Police and organizers said Sunday that extra security measures have been put in place to assure safety at the starting and finishing points of the event.

The popular London event, taking place on a sunny day in the British capital, is expected to draw some 36,000 runners hoping to finish the course through London's streets.

A 30-second moment of silence is planned before the start of the event to honor those injured in the Boston Marathon.

The Monday bombing there left three people dead and more than 170 injured, including many who are still hospitalized. In addition, a policeman was killed during the search for the two suspected bombers.