At least five people have been killed in clashes in Western Sahara, after Moroccan security forces broke up a protest camp in the disputed region.
The camp, for several thousand people near the territory's capital, Laayoune, was the biggest protest against Moroccan rule in the 35-year dispute.
Dozens of people were also injured in the violence, which later spread to the streets of Laayoune.
It came shortly before talks began in the US on the future of the territory.
The Gadaym Izik camp was set up about a month ago outside Laayoune as a protest by displaced Sahrawi people about their living conditions. It was home to more than 12,000 people.
Witnesses said security forces entered the camp in the early hours of the morning, using helicopters and water cannon to force people to leave.
"Hundreds of women and children were seen outside the camp leading towards Laayoune but a certain number of Sahrawi [local] men refused to go," one witness told the AFP news agency.
Moroccan officials said five security personnel had been killed in the unrest.
The pro-independence Polisario Front said Moroccan security forces had killed a 26-year-old protester at the camp, a claim denied by Morocco.
Television images showed protesters in Laayoune throwing stones at police and setting fire to tyres and vehicles. Several buildings, including a TV station, were also on fire.
One protester said: "Anger is boiling over. We are in the streets protesting against Morocco."
An official told Reuters the security forces had been forced to intervene after the demonstration turned violent. He said several people had been arrested.
Polisario heavily criticised the operation to close the camp.
The movement's self-appointed government is based in Algeria, from where its foreign minister, Salem Ould Salek, accused Morocco of acting "in a ferocious and undiscriminating fashion" against "defenceless civilians".
The unrest set a tense tone for the opening of UN-mediated talks in New York between negotiators from the Moroccan government and members of Polisario.
"It is highly unfortunate that this operation and the events preceding and following it have affected the atmosphere in which these talks are being held," said UN spokesman Martin Nesirky.
"We call on all parties involved to exercise the utmost restraint in the hours and days to come."
Ahmed Boujari, representing Polisario in New York, said the raid was "a deliberate act to wreck the talks".
"I hope that the UN Security Council will take up this affair," AFP quoted him as saying.
Moroccan officials have said they acted within the law.
Western Sahara, a former Spanish colony, is the scene of Africa's longest-running territorial dispute.
The phosphate-rich territory was annexed by Morocco after Spanish settlers left in 1975. Polisario fought a guerrilla war against Morocco until the UN brokered a ceasefire in 1991.
Rabat now offers to grant it autonomy, while Polisario is demanding a referendum on full independence.
The talks between both sites have been deadlocked for years, and the last meeting in February 2010 ended without any movement in the dispute.