By Prak Chan Thul
PHNOM PENH (Reuters) - Police used teargas, smoke grenades and water cannon to disperse demonstrators after a rally in Cambodia on Sunday to push for an investigation into a July election they say was fixed to favor the ruling party.
A human rights worker said he saw one protester shot dead and two others sustain bullet wounds to the legs as police moved in to arrest and disperse demonstrators. Police could not confirm the witness account.
Clashes broke out in two separate incidents as supporters of the opposition Cambodia National Rescue Party (CNRP) tried to remove razor-wire barricades. Protesters, some hurling rocks, were charged by riot police.
The violence and CNRP's refusal to heed instruction not to march beyond the protest site have taken a six-week standoff - one of the biggest tests of Prime Minister Hun Sen's three-decade grip on power - to a new and precarious level.
By nightfall, at least 1,000 protesters were camped out in the rain on straw mats and under makeshift tents, despite government orders to leave the capital's Freedom Park, the only venue in Cambodia where rallies are permitted.
The clashes with riot police, known for cracking down hard on dissent, added to political tension not seen for years, already heightened by the discovery of a bomb and some grenades around the city on Friday.
Hun Sen's Cambodian People's Party (CPP) won another five-year term, with 68 seats to the Cambodia National Rescue Party's 55, a greatly reduced majority that signals dissatisfaction with his authoritarian rule despite rapid economic growth in a country seen for decades as a basket case.
Sunday's rally of about 20,000 people was the second of its kind in eight days as demands for an independent investigation into complaints of fraud continued to be ignored.
The CNRP says it was cheated out of 2.3 million votes and would have won on July 28, and refuses to accept a ruling on Friday by the Constitutional Council that allegations of foul play had been investigated already and no new probe was needed.
The government and the National Election Commission, which CNRP leader Sam Rainsy accuses of collusion, are also both standing by the official result.
"They stole our votes, it's like stealing our lives," CNRP's deputy president, Kem Sokha, told supporters.
WAR OF ATTRITION
Police had earlier threatened demonstrators with jail and put razor-wire fences and fire trucks across roads in a failed bid to stop the march to Freedom Park from taking place.
Talks between the two parties, which were due to continue on Monday, have so far gone nowhere. A meeting on Saturday between King Norodom Sihamoni, Hun Sen and Sam Rainsy lasted just 30 minutes and produced no results.
It was unclear how long the opposition demonstration would last. Those wrapped in blankets and huddled under sheets in Freedom Park vowed to stay for at least three days.
"We're here to protest against the National Election Commission that stole our votes. They should be the referee, not the puppet of the ruling CPP," said Yong Ol, 43, who travelled by truck from southern Prey Veng province.
The CNRP refuses to quit but is running out of options and most analysts see the standoff as a war of attrition stacked in favor of a premier not known for compromise. Critics complain of what they say is the CPP's strong influence over Cambodia's independent institutions.
The opposition will try to paralyze the legislature by boycotting parliament's first session on September 23.
Hun Sen, 61, has been a dominant force in Cambodia for years and has taken credit for steering it away from a chaotic past towards economic growth and development.
But many urban youth born after the Khmer Rouge "Killing Fields" 1975-1979 rule see little appeal in his iron-fisted approach and are disillusioned by growing land evictions, labor disputes and graft and the country's close political ties with its top investor, China.
(Additional reporting by Pring Samrang; Writing by Martin Petty; Editing by Robert Birsel and Robin Pomeroy)