MONTREAL - Air Canada employees at Montreal's Trudeau airport joined a wildcat strike Friday morning that began a day earlier at Toronto's Pearson airport. The walkouts led to delays and the cancellation of dozens of flights in and out of both airports.

Striking Air Canada ground workers returned to work Friday after the company was granted an injunction by an arbitrator ordering an end to the labour dispute that disrupted flights across the country.

At least 60 flights were cancelled or delayed by Air Canada Friday in Toronto and another 30 in Montreal, according to the company's website. The flights were destined for Canadian and U.S. cities.

The wildcat strike began after three workers were suspended for heckling federal Labour Minister Lisa Raitt as she walked through Toronto's Pearson International Airport Thursday night, union spokesman Bill Trbovich said Friday.

When other workers heard of the suspensions they walked off the job and 37 of them were fired on the spot, he said. Baggage handlers joined the strikers in Montreal Friday morning.

He said the union didn't sanction or support the strike, which had also spread to Vancouver and Quebec City.

"We told them that if you go on strike it's illegal and you could lose your job if you continue to do this," Trbovich said.

The federal government has intervened in many Air Canada labour disputes, recently banning the company from locking out workers, and banning the pilots and mechanics unions from disrupting service.

The Harper government also intervened in contract talks with the airline's flight attendants and its customer service agents.

Raitt defended the legislation, saying it was done in the interest of the national economy.