A law restricting the use of the Internet by Belarusian firms and state institutions has come into force.
One aspect of the law seen as the most invasive requires Internet cafes and service providers to identify and keep track of all of their clients along with the web pages they visit.
Thirty-five specific websites are banned for Internet users at state institutions. Most are deemed pornographic or of an extremist nature. But some opposition political websites - including the pages of "Charter'97.org" and "Belarusian Partisan" - are also on the banned list.
Belarusian companies are required to use the Belarusian Internet domain - .by - in order to sell goods or services within Belarus.
Belarus's presidential administration says violators of this business provision could be charged with committing a civil offense.
Those who violate the law face a financial penalty equivalent to as much as $125.
Tax officials, police, and security services are authorized to initiate, investigate, and prosecute alleged violations.