Multiple Canadian government websites have been brought back online after they went dark for several hours in a hacking attack.
Tony Clement, a member of parliament and president of the Treasury Board, said that government servers had suffered a cyber attack on Wednesday.
Mr Clement said he did not know whether any data had been taken.
A video posted online claimed that the Anonymous hacking group was responsible for the attack.
"We are working very diligently to restore services and to find out the origination of the attack," Mr Clement said.
CTV News reported that the websites went down around midday (04:00 GMT) on Wednesday.
Some of the sites including those of Canada's spy agency and its parliament were restored around 15:00 local time.
Mr Clement told reporters that the attack was a distributed denial of service (DDOS) attack.
DDOS attacks are a common type of web attack that involves overloading a web server with too many requests.
A video posted on YouTube claiming to be uploaded from the so-called Anonymous hacking group says the group perpetrated the attack in retaliation for the recently-passed anti-terrorism law, known as C-51.
In the video, which appears to be highly produced, a computer-generated voice says the bill "is a clear violation of the universal declaration of human rights".
"Bill C-51 targets minority groups and dissidents alike," the voice says.
Bill C-51 was passed by the House of Commons in May and by the Senate on 10 June.
A few days ago, the IT department for the House of Commons warned staffers that they are "currently being targeted by several cyber attacks", CTV News reported.
Last summer, Canada's National Research Council was hacked in an attack blamed on Chinese hackers.