Hundreds of Turkish police in riot gear moved in against anti-government protesters in Istanbul's Taksim Square.
They were backed by water cannon and an arsenal of tear gas.
Protesters fought back with fireworks, stones, and petrol bombs.
It's the first time police have entered the square since demonstrations against plans to redevelop a nearby park spiralled into a wider backlash against the government.
Turkey has seen its worst riots in decades over the perceived authoritarianism of Prime Minister Tayyip Erdogan and his Islamist-rooted AK party.
A violent police crackdown against the protests has drawn Western criticism.
Erdogan has increasingly accused foreign forces of fuelling the troubles.
The raid on Taksim Square came a day after it was revealed Erdogan had agreed to meet those behind the original, peaceful, anti-park demonstration to try to end the unrest.
Since it began three people have been killed and about 5, 000 injured.
