The demonstrations began in late January after the United States and Canada imposed a new rule requiring cross-border truck drivers to be fully vaccinated to enter their respective countries.

Since then, the protests have grown into a broader condemnation of pandemic-related measures and the government of Prime Minister Justin Trudeau, who was recently reelected.

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Protesters in semi-trucks and other vehicles began descending on Ottawa on Jan. 28. They include those who oppose vaccines, vaccine mandates and other coronavirus restrictions; anti-government activists; conspiracy theorists; and far-right extremists.

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Demonstrators also set up a blockade to disrupt the flow of goods through two crossings along the U.S.-Canada border Tuesday — the Coutts border crossing linking Alberta to Montana, and the Ambassador Bridge linking Ontario to Detroit.