The International Brotherhood of Electrical Workers (IBEW), which represents about 750 Canadian National Railway Co. employees, says signal and communication workers have walked off the job across the country.

IBEW’s Steve Martin confirmed in a text that workers were legally on strike as of 11 a.m. local time on Saturday.

The IBEW gave a 72-hour strike notice Wednesday morning.

CN did not confirm that workers had gone on strike, but spokesman Jonathan Abecassis says the company has implemented an “operational contingency plan,” adding that operations are continuing “safely and at normal levels.”

The Montreal-based company says it continues to encourage the union to resolve sticking