OTTAWA - Federal workers who had been forced to work from home after a bed bug infestation were mostly back in the office Tuesday.

Last week, hundreds of employees stayed out of the building on Cremazie in Gatineau because of the infestation. They work for Immigration, Refugees and Citizenship Canada.

On Tuesday the union representing the workers emailed CTV News saying that all workers were back at their work stations after the bed bug treatments.

Workers on the third floor were delayed by a couple of hours Tuesday. That floor was the last to be treated for bed bugs.

The union also said the IRCC will be testing the building regularly, and checking for bed bugs in other buildings it operates.

The union says it is also offering tips to employees on how to stop the spread of bed bugs at work and in their homes.