Canada's industrial relations board on Saturday ordered striking rail workers back on the job and imposed binding arbitration to settle labor disputes at two major freight carriers that threatened to upend the North American economy.

Stoppages began Thursday morning at both Canadian National Railway (CN) and Canadian Pacific Kansas City (CPKC), locking out nearly 10,000 workers with the Teamsters union.

Prime Minister Justin Trudeau's government moved quickly to end the strikes, sending the disputes to the Canada Industrial Relations Board (CIRB) to be resolved by an arbitrator.