Hundreds of trucks, recreational vehicles and cars circled the outskirts of Washington D.C. on Sunday, aiming to slow traffic around the U.S. capital as part of a protest against COVID-19 restrictions.

The "People's Convoy," which originated in California and has drawn participants from around the country, is calling for an end to all pandemic-related restrictions. It was inspired by demonstrations last month that paralyzed the Canadian capital Ottawa.

Leaders of the convoy said that on Monday they will again slowly drive the Beltway, a 64-mile highway that encircles the city, though details of when the action would take place were not known.

The convoy, more than three kilometers long, slowed traffic at points along the Beltway by late Sunday morning, but did not bring it to a standstill. It returned to the Hagerstown Speedway in the afternoon, according to messages on the convoy's Telegram channel.

The convoy's protest against vaccine requirements and other pandemic restrictions has been undercut in recent weeks as major U.S. cities have rolled back mask mandates and other measures against COVID-19 with infections and hospitalizations declining dramatically.

U.S. President Joe Biden signaled in his State of the Union speech on Tuesday that the country was entering a new phase of the pandemic without business lockdowns, school closures or other daily disruptions.

U.S. federal law enforcement agencies have been coordinating with state and local authorities for weeks in preparation for the possible arrival of the convoy, according to one U.S. official who requested anonymity.