Thousands of Iranians staged on Wednesday a rally outside the site of the former US Embassy to commemorate the 25th anniversary of the US hostage crisis.

The demonstrators shouted anti-US slogans as they marched through Tehran's streets to the embassy compound. Some protestors set the US national flags ablaze on the spot.

On Nov. 4, 1979, a group of extremist students broke into the US Embassy, which they labeled "den of espionage," and took 66 people as hostage.

The students had demanded that Washington extradite exiled King Mohammad Reza Pahlavi to Iran.

The United States, after a failed rescue operation, was forced to make concessions, including the return of Iran's money and the exiled king's assets frozen in the United States.

The hostages were freed in January 1981, but the incident prompted the United States to sever its diplomatic relations with the Islamic Republic.

The United States has labeled Iran as part of the "axis of evil," accusing it of sponsoring terrorism and secretly developing nuclear weapons.

In return, Tehran terms Washington as the "enemy of Islam" and "real terrorist."