Cambodian opposition supporters have taken to the streets for a second day, after thousands of protesters marched to the United Nation's human rights office in the capital, Phnom Penh.
They are urging the world body to intervene in the country's political deadlock, and opposition leader Sam Rainsy said they had handed over a petition to the UN on Wednesday.
"We have asked the United Nations to help to find justice for the Cambodian people," he told reporters. "They promised they will send those petitions to the UN headquarters in New York."
The opposition is protesting against the ruling party and calling for an investigation into poll results in July that returned Prime Minister Hun Sen to power.
Al Jazeera's Rob McBride said around 20,000 protesters had camped out over night to Thursday despite an order against them telling them not to do so. Security forces kept a low profile, allowing people to protest peacefully.
Our correspondent added that the ruling party refuses to budge, and that the election result was expected to stand.
"It is difficult to see how they will be moved out of that position as they maintain a hegemonic grasp on power," he said.
Official election results extended Hun Sen's 28-year rule and gave his party 68 seats in parliament, compared to 55 for the opposition Cambodia National Rescue Party. The CNRP says it was cheated out of a victory and will boycott the new parliament until the government has met its demands.
More than 1,000 police and soldiers were put on duty for the protest, which authorities said they would allow as long as there is no violence.
Military police spokesman Kheng Tito has said authorities were ordered to take a softer line on this rally than on one in September, when clashes with police left one man dead and several injured.
Human Rights Watch echoed the CNRP's calls for an investigation.
"Cambodia's donors and other countries should publicly press the Cambodian government to set up an independent, internationally assisted investigation into disputed national elections in July 2013," the New York-based rights group said in a statement on Wednesday.
The group's Asia director, Brad Adams, criticised France, Australia and Japan for sending congratulatory letters to Hun Sen, saying in the statement that "democratic leaders should skip the congratulations and instead insist on an independent investigation into malfeasance at the polls."