Air Canada's operations appeared to be back to normal early Monday after a weekend that saw an unusually high number of pilots call in sick, causing some flights to be cancelled or delayed.

The airline's online departures schedule for Pearson International Airport in Toronto showed just a few flight delays.

Airline spokesman Peter Fitzpatrick said while weather, a fire at Pearson and other factors affected operations, "some impact was the result of a higher-than usual pilot book-offs."

Air Canada said Sunday that it had asked the Canada Industrial Relations Board to intervene, saying it could not "condone such activities as part of industrial action to disrupt our operations."

The pilots' union did not immediately respond to requests for comment.

Air Canada is in the middle of a bitter labour dispute with its pilots that prompted the federal government to step in earlier this month.

In the face of a threatened lockout by pilots and a strike by ground crew, the federal government referred the matter to the Canada Industrial Relations Board and also passed back-to-work legislation last week that referred the disputes to arbitration.