Thousands of Cambodian opposition supporters have launched fresh demonstrations against Prime Minister Hun Sen's highly contested re-election in July, calling for a new poll to settle allegations of vote rigging.

Around 5,000 protesters gathered in a park in the Capital city of Phnom Penh on Sunday, waving Cambodian flags and banners.

"A new election is the peaceful and democratic way forward," Ho Vann, a senior opposition member told the crowd.

"We want the government to call a new election now because July's election was marred by widespread voting fraud and there is no investigation into it so far," protester Tep Chan Thaiya told the AFP news agency.

Cambodia's opposition, the Cambodia National Rescue Party (CNRP), had previously called for an independent probe into alleged vote rigging during the election that saw Hun Sen's nearly three-decade rule extended.

But Hun Sen's government rejected an investigation, prompting the opposition to call for elections.

One protester died and several others were injured when opposition supporters took to the streets immediately after election results were released in July.

'Hun Sen Step down'

This time, there was only a light security presence.

Protestors listened to a speech given by opposition leader Sam Rainsy, who arrived in the afternoon, before beginning a march through the capital.

"We are demanding a re-vote because the previous election is not acceptable," Rainsy said to cheers. "The (July) election is not fair. We cannot accept it," he added before leading a chant of "Hun Sen step down."

Rainsy's CNRP has boycotted parliment since Sen's re-election to protest against the alleged vote-rigging.

According to official results of the July polls, the ruling Cambodian People's Party (CPP) won 68 seats against 55 for the opposition.

Parliament approved a new five-year term for Hun Sen in late September, despite the absence of opposition members of parliament.

Source: AFP