Waving Iranian flags, chanting "Death to America" and burning US and Israeli flags, hundreds of thousands of people have poured out onto the streets across Iran, marking the date that's considered victory day in the country's 1979 Islamic Revolution.
On February 11 that year, Iran's military stood down after days of street battles, allowing the revolutionaries to sweep across the country while the government of US-backed Shah Mohammad Reza Pahlavi resigned and the Islamic Republic was born.
In Tehran, crowds streamed in the rain from a dozen of the capital's far-flung neighbourhoods to mass in central Tehran Azadi, or Freedom Square, on Monday, waving Iranian flags and chanting "Death to America" - a chant that has been standard fare at anti-US rallies across Iran.
Chants of "Death to Israel" and "Death to Britain" followed, and demonstrators burned US and Israeli flags
The 10 kilometre-long downtown Enghelab, or Revolution Street, in Tehran was decorated with huge balloons as loudspeakers blared out revolutionary and nationalist songs to encourage people to join the rallies.
This year's anniversary comes as tensions rise with the United States and Iran grapples with the aftermath of President Donald Trump's pullout last May from the 2015 nuclear deal between Iran and world powers and tough US economic sanctions, re-imposed in November.
Speaking from a podium in central Tehran, Iranian President Hassan Rouhani addressed the crowds for nearly 45 minutes, lashing out at Iran's enemies - America and Israel - and claiming their efforts to "bring down" Iranians through sanctions will not succeed.
"The presence of people in this celebration means that plots by the enemies ... have been defused," Rouhani said. "They will not achieve their ill-omened aims."
In the backdrop to Monday's marches, the military displayed Iranian-made missiles, which authorities showcase every year during anniversary celebrations and which now have a range of up to 2000 kilometres and are able to Israel and US military bases in the region.
Over the past decade, Iran has frequently test-fired and displayed missiles, sent several short-lived satellites into orbit and in 2013 launched a monkey into space.
Rouhani also promised the crowds that Iran would overcome the economic hardship amid the country's spiralling economy and the newly imposed US sanctions.
