Cambodia's main opposition party made significant gains in local elections Sunday which could threaten Prime Minister Hun Sen's grip on power.
Announcing preliminary results, opposition party spokesman Yim Sovann said his party won about 46 percent of the popular vote - up from 30 percent in the last local elections five years ago.
"This is a huge victory for the Cambodia National Rescue Party," Sovann told a news conference.
A pro-government news site said preliminary results suggested the opposition had won a little more than one third of the communes.
Official results will be announced June 25.
The vote is also seen as a showdown between the two major parties amid threats of civil war and a crackdown on political dissent in the lead-up to national elections slated for the middle of next year.
Prime Minister Hun Sen and his Cambodian People's Party (CPP) see the communal poll as an important test of their popularity, which has been under stiff pressure from a burgeoning youth vote and changing attitudes.
Supporters of the opposition Cambodia National Rescue Party (CNRP) have been buoyed by their party's standing at national elections in 2013 when the ruling CPP was returned to power, but with its majority reduced to 68 seats, from 90, in the 123-seat National Assembly.
The CNRP scored 55 seats, annihilating all the smaller parties in its path, after Cambodia's youth sided with the opposition and demanded change. More than 70 percent of this country's population is under the age of 30, a legacy of a post-war baby boom.
Bo Pao, Executive of Youth Education for Development and Peace (YEDP), said differences between young and old are taking its toll. Older voters are attracted to the security provided by the CPP, which ended the wars in 1998 and ensured a peace that has enabled economic growth.
The local nature of these elections has not stopped Hun Sen from weighing in at the national level, warning Cambodia could return to war if the CPP was to lose. Politics has also been marred by the beating of opposition parliamentarians, criminalization of defamation laws and banning of anyone with a criminal conviction from contesting elections.
Defamation suits and the constant threat of prison prompted opposition leader Sam Rainsy to resign and return to self-imposed exile in France with his deputy, Kem Sokha, taking up the leadership role of the CNRP.
Hun Sen has also curtailed political street rallies.
The U.S. State Department has called on the government to avoid threats and political intimidation.
But hopes are high that there will be no repeat of the violence that followed the 2013 general election, when at least five people were killed.
Son Chun Chuon, program director at Khmer Kampuchea Krom for the Human Rights and Development Association, said this year's commune elections were better organized than previous efforts following reforms to the National Election Committee (NEC).
About 12,000 local positions, including commune chiefs and district counselors, are being contested by 12 political parties.