Thousands of Greek protesters in Athens chanting anti-US slogans, on November 17, 2022. (AFP)

Greek protesters burned the American flag on Thursday during popular marches on the streets of the capital Athens, in commemoration of the forty-ninth anniversary of the student uprising against the US-backed military rule in 1973.

The demonstrations culminated in front of the US Embassy, in protest of Washington's support for the Greek military dictatorship during the Cold War, with protesters chanting slogans demanding the exit of NATO from Ukraine.

The marches were led by a group of demonstrators carrying bloodstained Greek flags, while about five thousand police officers were deployed on the streets of the capital following confrontations with protesters.

Some 5,500 people marched in the capital under the supervision of security forces, as violence often broke out on the sidelines, the police said.

Huge riot police presence and roads closed towards the #US embassy in #Athens, #Greece, as the left leaning politically people are protesting against the 1973 student uprising that was brutally crushed by the military junta. pic.twitter.com/ssHoy2ui0r
— Sotiri Dimpinoudis (@sotiridi) November 17, 2022

Video footage from earlier today, showing you a huge left leaning protest of thousands of people, who were marching from Syntagma Square towards the #US embassy building in #Athens, #Greece. 📹: @savvaskarma pic.twitter.com/DI7IX1dBaY
— Sotiri Dimpinoudis (@sotiridi) November 17, 2022

Thousands of people demonstrate yearly on the anniversary of a deadly crackdown on a 1973 student revolt against a US-backed junta.

"Past demonstrations have turned violent and have involved destruction of property," the US Embassy in Greece claimed in a statement.

"The embassy has advised its personnel to avoid the areas of the demonstrations and will close early," it said.

The annual protests mark the day when at least 24 people were killed at the Athens Polytechnic when the junta sent troops and police forces against a pro-democracy student uprising.

The brutal crackdown was a shock to Europe and is considered to have broken the dictatorship's grip on power, leading months later to the restoration of democracy.

Each year, the demonstrators hold the bloodstained Greek flag that flew that night over the Polytechnic's iron gate, which was crushed by a tank.

The bloodstained Greek flag

In recent years, protesters have used the anniversary to protest against the harsh austerity measures imposed on Greece by its international creditors after the global financial crisis.

Last year's demonstration saw around 20,000 people taking part in Athens, with another 14,000 in Thessaloniki.

This year, the commemoration began with a wreath-laying ceremony at the Athens Polytechnic University, the site of the bloody incident on November 17, 1973, when tanks stormed the gates to crush the student uprising that heralded the end of the military junta.

On Thursday, Prime Minister Kyriakos Mitsotakis, whose government is embroiled in a "wire-tapping scandal", said the uprising "established the most complete democracy our country has ever known."