When users attempted to access those sites, they saw the message: "This Website has been blocked by the iraqi ministry of communications."
Although an official reason was not given, the Kuwait News Agency speculated the sites were closed to prevent invading Islamic State of Iraq and Syria forces from using them for communications purposes.
ISIS militants seized several Iraqi cities this week and are heading for Baghdad, the capital. The group, an affiliate of al-Qaida, has employed the Internet in broadcasting videos and photographs of its actions.
The Iraqi Ministry of Communications also announced the Internet would be unavailable "in all parts of Iraq" beginning Friday night, claiming the reason was maintenance of optical cable along the country's border with Turkey.