Thousands of Iranians chanting anti-US slogans will take to streets of the capital on Tuesday for a mass rally marking 30 years since the Islamic revolution toppled the US-backed shah. Crowds will converge on Azadi (Freedom) Square to join members of the Basij Islamist paramilitary force for the annual demonstration at a time of continuing tense relations between Tehran and Washington. The United States and other world powers suspect Iran's controversial nuclear programme is aimed at making atomic weapons, but Tehran says it is civilian and peaceful. Each year the February 10 anniversary commemorates the uprising and victory of the revolution, sealed on that date 30 years ago, when the army declared its neutrality.