Turkish riot police have used tear gas to disperse thousands of anti-government demonstrators who gathered on Taksim Square in Istanbul, after a day of sporadic clashes.
Many protesters regrouped in nearby Gezi Park, where unrest continued into Wednesday morning.
At dawn, bulldozers moved into Taksim Square to clear away debris, barricades and makeshift shelters.
Protests began 13 days ago over the redevelopment of Gezi Park.
They then widened, with demonstrators accusing Prime Minister Recep Tayyip Erdogan of becoming increasingly authoritarian and trying to impose conservative Islamic values on a secular state.
Mr Erdogan is due to meet a group of people - including an actress, a singer and a writer - who he hopes can mediate with the protesters.
It had been suggested he would hold talks with protest organisers, but they told the BBC that they had not been approached by the prime minister - and would refuse to meet him even if they were.
They added that they did not recognise any of the group that Mr Erdogan was due to meet as representatives of the protesters in the park.
Thousands converged on the square as night fell on Tuesday and were repelled by water cannon, rubber bullets and tear gas.
Many peaceful demonstrators were also caught in the clashes, and volunteers set up makeshift clinics to treat anyone injured.
Many of the dispersed demonstrators sought shelter in nearby areas, including Gezi park. Police said they did not plan to enter the park.
Throughout the day, riot police had repeatedly clashed with protesters throwing bottles, rocks and firebombs.
Security forces cleared the square, only for the demonstrators to return.
Mr Erdogan defended the police action, saying that an environmental movement had been hijacked by people who wanted to harm Turkey.
In a televised speech, he said: "To those who... are at Taksim and elsewhere taking part in the demonstrations with sincere feelings: I call on you to leave those places and to end these incidents and I send you my love.
"But for those who want to continue with the incidents I say: 'It's over.'
"As of now we have no tolerance for them."
The protests began on 31 May.
The Turkish Human Rights Foundation says four people have been killed, including one policeman.
Some 5,000 protesters have been treated for injuries or the effects of tear gas, while officials say 600 police have also been injured.
Protests have also occurred in the capital, Ankara, with smaller demonstrations in many other cities.
Police in Ankara have used water cannon and tear gas to break up demonstrations almost every night.