Access to Google's email service, Gmail, and search engine has been restricted in Iran, the BBC reported.
Iranians are already prevented by a firewall from accessing various Western sites.
The latest restriction comes as protests continue across the Muslim world against a U.S.-privately produced controversial anti-Islamic movie posted on YouTube that mocks the Prophet Muhammad.
A government deputy minister announced the ban on Sunday on state television.
"Google and Gmail will be filtered nationwide, and will remain filtered until further notice," the BBC quoted an adviser to Iran's public prosecutor's office Abdul Samad Khoramabadi, as saying on state TV on Sunday.
Text messages with similar warnings were also sent to nationals’ mobile phones.
Following protests and claims of vote fraud after Iranian President Mahmoud Ahmadinejad’s re-election in mid-2009, Google-owned YouTube site has been censored in Iran. Censorship is also applied to the websites of the Guardian, BBC and CNN, as well as some other web services, including Facebook and Twitter.
Innocence of Muslims triggered protests in the Muslim world. In Libya, they led to an attack on the U.S. consulate that left Ambassador Christopher Stevens and three others Americans dead.
Search giant Google has already blocked access to the video in several Islamic countries.