Authorities are stepping up patrols on a trail between Washington and Maryland following a number of attacks in recent weeks.
Police say there have been four attacks, including assaults and robberies, on a stretch of the 8-mile Metropolitan Branch Trail that runs from Silver Spring, Md. to Union Station in Washington.
The last incident occurred last week when two men tried to use a Taser on a bicyclist just south of Rhode Island Avenue.
Police say they have not determined whether the attacks are related. The increased patrols will continue indefinitely.