The Canada Revenue Agency is reporting that all of its online services are back in service after being down since Friday afternoon due to an "internet vulnerability" that was discovered during website maintenance.

In an update posted on the CRA website, the agency said that as of 5 p.m. Sunday, individuals and businesses have been able to file electronically, make payments and access all other digital services.

An earlier message on the Canada Revenue Agency's website. The agency took its online services down on Friday at 1 p.m. (CRA)

"The CRA acted quickly to temporarily take down our online services, including electronic filing, and put in place the necessary maintenance security patches to ensure that all information and systems remained safe," the statement read.

"We took this action as a precaution, not as the result of a successful hack or breach."

The agency said tax returns that had already been filed were processed normally while the services were down and that Canadians should not "expect a delay in getting their refund."

The CRA first took its website down as a precaution at midnight on March 10.

It said it has worked around the clock over the past two days with other government departments to address the issue.

Affected services included My Account, My Business Account, Represent a Client, the MyCRA mobile application, the MyBenefits mobile application, Netfile, EFILE and Auto-Fill My Return.

Statistics Canada also took its website offline, although in a statement, a spokesperson said that systems used to conduct surveys were separate and not affected by the outage. The agency said the issue would not affect the distribution of its daily morning statistical release, which is also available through social media and to email subscribers.

Alain Belle-Isle, spokesperson with the Treasury Board of Canada, said in a statement to CBC News the necessary fixes to the issue "were applied and tested" before the affected sites were brought back online.

"The government of Canada takes the privacy of Canadians very seriously and ensuring the security of Canadians' personal information is our priority," he said.