Protesters have clashed with Turkish police in Istanbul, after riot squads used tear gas and water cannon to eject demonstrators from Gezi Park.
The protesters quickly fled the park, but later erected barricades across nearby streets and lit bonfires.
Witnesses said it was one of the worst nights of unrest since the park was occupied 18 days ago.
Police blocked off the Bosphorus Bridge to stop demonstrators reaching Taksim Square, where the park is located.
Clashes continued into Sunday morning in the streets around the square, eyewitnesses say. On the square itself, bulldozers went to work, clearing away the protesters' abandoned barricades.
Thousands of people also took to the streets of the capital, Ankara, to express support for the protests.
Riot police moved in hours after Prime Minister Recep Tayyip Erdogan warned protesters who had set up camp in Gezi Park to leave.
Plans to cut down trees in the park to make way for a shopping centre and replica military barracks sparked a wave of broader anti-government unrest.
Despite a promise by Mr Erdogan to halt the development plan until a court ruling on the issue, the protesters had vowed to stay there until their wider demands were met.
As police advanced into the park wearing riot shields and gas marks, most of the protesters left of their own accord to avoid getting hurt, the BBC reports.
Some regrouped in nearby streets while local residents took to their balconies or leaned out of windows banging pots and pans and drivers sounded horns in support of protesters.
Earlier, in a speech in Ankara, Mr Erdogan told tens of thousands of supporters of his AK party that it made no sense for demonstrators to stay in Gezi Park as the matter is now in the hands of the courts.
He dismissed the wave of demonstrations as part of an organised plot against him.
One protest group responded to Mr Erdogan's speech by calling for another mass rally in Taksim Square. Istanbul is also set to host an AK party rally on Sunday.
Demonstrators have accused Mr Erdogan's government of becoming increasingly authoritarian and of trying to impose conservative Islamic values on a secular state.
Five people have died and thousands have been injured since the protests began on 31 May.
The police crackdown on protesters in Istanbul, Ankara, and other towns and cities has drawn international concern, especially from Europe.