Iranian people poured into the streets on Monday morning to hold nationwide rallies commemorating the 40th anniversary of the victory of the 1979 Islamic Revolution.
People from all walks of life have attended the countrywide rallies.
Iranians in the capital, Tehran and more than 1,000 other cities and towns and in 4,000 villages are attending the rallies with flags of Iran and banners in support of the Islamic Republic.
In the capital, the demonstrators rally across 10 main routes to reach the Azadi (Liberty) Square to celebrate the Islamic Revolution's victory which toppled the US-protégé regime of Pahlavie dynasty.
Hundreds of foreign guests, including journalists have travelled to Iran to attend and cover the event.
High-ranking Iranian officials including heads of all branches of power as well as members of all political parties, lawmakers and military officials are taking part in the demonstrations.
The demonstrators chant 'Death to US' and 'Death to Israel' slogans in the mass rallies in the capital and other cities.
President Hassan Rouhani will address the ralliers at the Azadi Square.
The 10-day period from the Imam Khomeini's return from Paris to Tehran on February 1, 1979 until the revolution’s victory on February 11 is celebrated in Iran annually and is dubbed as the Ten-Day Fajr (Dawn).