The main mobile telephone network in Iran was cut in the capital Tehran Saturday evening while popular Internet websites Facebook and YouTube also appeared to be blocked, correspondents said. The communication cuts came after President Mahmoud Ahmadinejad won a landslide re-election victory, sparking rioting in the streets by opposition supporters who claimed the result had been rigged.

The mobile phone network stopped working at 10:00 pm (1730 GMT), just before Ahmadinejad went on television to declare the election a "great victory" and even as baton-wielding police were clashing with protestors in the streets of Tehran, according to witnesses.

Iran has two national networks run by state-owned MCI (Telecommunication Company of Iran) and the private firm Irancell. Several Iran-based users logging on via different Internet service providers, meanwhile, said they could reach neither Facebook nor YouTube -- the two websites used effectively by young supporters of Ahmadinejad's moderate rival Mir Hossein Mousavi. Mousavi complained bitterly on Saturday against "vote rigging" in the election, unleashing violent clashes between his supporters and anti-riot police. Scores of users started posting pictures and videos of the protests on both sites shortly after they broke out in Tehran's streets.