Greece is marking the 46th anniversary of the bloody Athens Polytechnic Uprising which eventually led to the collapse of a brutal ruling military junta.

The annual commemoration is usually marred by violence, with police and demonstrators clashing at the end of the traditional march in Athens.

Tensions between police and demonstrators have already emerged with accusations of police brutality thrown at the authorities, raising fears that clashes could be even more violent this year.

A demonstration in Athens on Sunday will bring an end to the three-day commemoration. It will start at 16:00 CET from the Technical University and end near the American Embassy.

What happened at the Athens Polytechnic Uprising?

On November 14, 1973, a few dozen students at the Athens Polytechnic University went on strike to denounce the junta which had grabbed power in a military coup d'état in April 1967.

Under dictator Georgios Papadopoulos, a former army colonel, martial law had been imposed in the country, the press muzzled and political opponents jailed, tortured or forced into exile.

The students seized telecommunications equipment and began broadcasting anti-government messages, prompting thousands to protest the following day.

Unlike in February of the same year, when another student protest had resulted in a violent police crackdown, authorities were this time unable to quickly enter the building but undercover police and snipers were deployed to the area.

They started attacking the crowd on November 16th but undeterred protesters refused to evacuate. In the early morning of November 17, battalions of marines and paratroopers were sent to the scene and a tank burst open the main gates of the university.

At least 24 civilians were reportedly killed outside the campus although the number is believed to be much higher.

What happened next?

Although the protest had been severely crushed by the junta, it sowed disunity within the government. A counter-coup organised by hardliner Dimitrios Ioannidis overthrew Papadopoulos in November of that same year.

But Ioannidis's rule was short-lived. A coup d'état he engineered to annex Cyprus in mid-July 1974 led Turkey to invade the small Mediterranean island and the military junta to implode.

A caretaker government led by former Prime Minister Konstantinos Karamanlis — who had been living in self-imposed exile in Paris, France since 1963 — was installed on July 23.

Parliamentary democracy returned to the country with legislative elections taking place on November 17, 1974.