Ottawa's police chief resigned on Tuesday after criticism that he did not do enough to stop Covid-19 protests that have paralysed Canada's capital city and forced Prime Minister Justin Trudeau to invoke emergency powers.

A trucker-led movement calling on the government to lift vaccine mandates has occupied parts of downtown Ottawa since late January and blocked US border crossings, inspiring similar protests around the world even as Canada moves to lift some health restrictions.

Protesters retreated from the Ambassador Bridge to Detroit and two other crossings after threats of fines and jail time. But...