A man was found dead on a flyover in the capital's southern part after a clash between Cambodian police and opposition protestors at Sunday night, eye witnesses said.

Police clashed with opposition party protesters at the flyover at around 8:00 pm (local time) when they had tried to break through the police's barbed wire barricades.

Police had fired tear gas to disperse hundreds of protestors as they had thrown stones at them.

A well-known news website DAP took the photo of the dead man whose head and body stained with blood.

Police has not determined the cause of the man's death, the DAP news said.

Neither National Police spokesman Kirt Chantharith nor National Military Police spokesman Kheng Tito could be reached for comments on Sunday night.

Meanwhile, the opposition Cambodia National Rescue Party (CNRP), which organized a mass protest at the Freedom Park, issued a statement on Sunday, denying that his party supporters held a protest outside the Freedom Park.

"Any opportunist who causes trouble and chaos outside the Freedom Park, the CNRP will not take any responsibility, and the party appeals to the authorities to take legal action against those opportunists," the statement said.

It was the second clash between the police and protestors after the first one occurred in the afternoon, when hundreds of protestors had removed police's barbed wire barricades in order to march through a street in front of the Royal Palace.

During the afternoon's clash, police had fired tear gas and water cannons to disperse protestors as they tried to remove the barricades of barbed wire and threw stones at the police, said National Military Police spokesman Kheng Tito, adding that one police officer got injured on his head due to a stone thrown by protestors.

The Sunday protest aimed to reject the July 28 election results that showed the ruling Cambodian People's Party (CPP) of long- serving Prime Minister Hun Sen got victory with 68 parliamentary seats and the CNRP of long-time opposition leader Sam Rainsy received the remaining 55 seats.

The CNRP claimed that its party should win 63 seats, with the CPP getting 60 seats if alleged irregularities during the poll were fairly investigated.

At the Freedom Park in Sunday morning, Sam Rainsy told about 20, 000 supporters that the party would boycott the opening session of the parliament on Sept. 23 if there was no proper solution to the alleged irregularities during the election.

Sam Rainsy and Hun Sen would meet for the second time on Monday at the National Assembly in a last-ditch attempt to break through the political stalemate, the two parties said.

Prime Minister Hun Sen has said that his party has enough lawmakers to override any opposition parliamentary boycott and form a new government.