Istanbul: A Turkish artist on Saturday unveiled a two-story-high mural featuring those killed in protests two years ago over an Istanbul park that spiraled into nationwide demonstrations against the leadership of Tayyip Erdogan.

The 5-by-10-metre painting by Haydar Ozay was unveiled on the second anniversary of the protests that began as an effort to stop bulldozers from razing Gezi Park, one of the few green spaces of Istanbul, to build a shopping mall.

Unrest quickly spread across Turkey, a revolt against what protesters said was the increasing authoritarianism of Erdogan's decade-long rule.

The then prime minister accused a coalition of ‘anarchists, terrorists and vandals’ of orchestrating the demonstrations.

Art was a central element of the protests, which erupted at the end of May 2013. Graffiti lampooning Erdogan and other spontaneous artistic expressions flourished during the weeks protesters occupied the park and the adjacent Taksim Square.

‘People had felt so much pressure that there was a volcano-like explosion of creativity. Gezi was the perfect stage,’ said Ozay, 46, who knew the park from his childhood when his father was its gardener.

‘Gezi has surprisingly transcended its own duration and is still unfolding, especially in art.’

Ozay's massive, brightly colored work on canvas depicts figures familiar to protesters in swirling abstract brushstrokes. A woman in a red dress is tear-gassed; Berkin Elvan, who died aged 15 after he was hit in the head by a police gas canister, plays marbles.

At least seven people died in the protests, which according to police records were attended by 3 million of Turkey's 77 million people.

After a police crackdown, Erdogan moved swiftly to reassert his authority. His ruling AK Party swept to victory in municipal polls in March 2014 and in August he won the nation's first direct presidential election.

As head of state, he is constitutionally barred from party politics, but critics say he is actively campaigning for the AK Party ahead of a June 7 general election.

Still, Gezi sowed the seed for other political movements, including the People's Democratic Party, which hopes to win 10 percent of the vote to clear a threshold and enter parliament on a leftwing platform that includes some protester demands.

Another after-effect was the trials of hundreds of people for taking part in the protests. Most have been acquitted, but cases against dozens of people continue, said lawyer Can Atalay.

Ozay, who spent a year painting the mural, said he is not worried about prosecution because art is typically given greater license in Turkey than other forms of protest.

Taksim Square is off limits to crowds on the anniversary due to a police cordon, so Ozay is displaying the painting at the Union of Chambers of Turkish Engineers and Architects, whose members helped lead the protests.