An anti-vaccine trucker convoy like the one in Canada that has shut down Ottawa could be coming to the U.S. starting Super Bowl Sunday, warns the Department of Homeland Security.

The warning, which states that “the convoy could severely disrupt transportation, federal government, and law enforcement operations through gridlock and potential counterprotests,” was circulated to law enforcement nationwide on Tuesday, according to Yahoo!News.

The DHS, it said, “has received reports of a convoy of truckers planning to potentially block roads in major metropolitan cities in the United States in protest of, among other things, vaccine mandates for truck drivers.”

Brian Base, one of the leaders of the U.S. convoy, on Feb. 7 posted to his personal Facebook page that the protests would be starting imminently.

“Can’t wait. See you soon California.”

“United we stand, divided we fall! Hope to see you all in Coachella.”

Canadian lawmakers expressed increasing worry Tuesday about the economic effects of disruptive demonstrations after the busiest border crossing between the U.S. and Canada became partially blocked by the trucker convoy.

The blockade at the Ambassador Bridge between Detroit and Windsor, Ontario, prevented traffic from entering Canada while some U.S.-bound traffic was still moving, Public Safety Minister Marco Mendicino said, calling the bridge “one of the most important border crossings in the world.” It carries 25% of all trade between Canada and the United States.

The daily demonstrations staged by the so-called Freedom Truck Convoy are centered in Ottawa, where demonstrators have used hundreds of parked trucks to paralyze parts of the capital for more than 10 days. Protesters have said they will not leave until all vaccine mandates and COVID-19 restrictions are lifted.

An anti-vaccine convoy is also forming in France, according to media reports.

About 200 protesters assembled in a parking lot in Nice, on France’s Mediterranean coast, on Wednesday, with many displaying Canadian flags in a nod to the truckers in Canada who are protesting their government’s COVID-19 restrictions.

The U.S. group “intends to start in California as early as mid-February and travel to Washington, D.C., as late as mid-March, reportedly gathering truckers as they travel across the country,” according to the DHS.

Truckers from the Ottawa may also head to Washington to participate.

Information from the Associated Press was used in this report.