Iranian police fired tear gas Thursday as hundreds of demonstrators defied warnings staged a march to commemorate the anniversary of bloody student unrest in 1999, witnesses said.
Police fired the gas as hundreds of people were moving in from several streets in the city and trying to converge in front of Tehran University, one witness told AFP.
A crowd of 200 to 300 people chanted "death to the dictator" and urged the police to support them, another witness said