Iranian state radio says seven people were killed by gunfire yesterday during a massive rally in Tehran yesterday to protest against the country's presidential election results.

Tens of thousands of people defied a government ban on demonstrations to take to the streets and express their anger at the re-election of President Mahmoud Ahmadinejad.

The country's ruling Guardian Council is carrying out an investigation into alleged voting irregularities at the request of the losing candidate, Mir Hossein Musavi.

Iranian radio says the seven people killed yesterday were hit by gunfire in the west of the city when protestors "tried to attack a military location".

Witnesses say the shooting came from a compound for volunteer militiamen linked to the powerful Revolutionary Guard.