At about 5:30 p.m., officers were monitoring about 30 bicyclists who were reportedly impeding traffic on East Washington Street.
The bicycles were taking up two lanes of traffic, according to police. An officer advised the riders to move. Several people refused and five citations were given for minor traffic violations.
Jason Dodge, 41, and Ian Dalling, 19, were arrested for allegedly delaying or resisting officer commands, according to police.
The Petaluma residents were taken to the Police Department where they were booked and issued citations to appear in court.