A statement Wednesday from Mayor Gregor Robertson says additional details are not available as the matter is being investigated by the RCMP.
Vancouver police, meanwhile, issued a release saying they've taken the "unusual steps" of securing public works yards and job sites due to a threat against a City of Vancouver employee.
Sgt. Randy Fincham says that police do not believe there is a risk to the general public.
Fincham would not provide any information about the nature of the threat.
Robertson called the incident challenging for city staff and said they have been asked to "carry on business as usual."
"The City of Vancouver has experienced a serious incident today," he said.
"This kind of incident is very challenging for the thousands of hardworking staff who come to work every day to make Vancouver a better place, and their safety and well-being is my utmost concern."