Witnesses said Cambodian riot police hit and kicked protesters as they marched in the capital Wednesday to demand compensation for being evicted from their homes to make way for a luxury development.
At least five protesters were injured, all of them women. Police in Phnom Penh blocked about 100 protesters from marching to the local offices of the World Bank and the European Union.
Their dispute is a high-profile example of the evictions and land grabs that have become a volatile social problem nationwide, with deadly force sometimes employed and allegations of corrupt deals.
The protesters said they were residents of Phnom Penh's Boueng Kak lake area whose land was awarded by the government to a Chinese company for commercial development with a hotel, office buildings and luxury housing.
The protesters demand land titles they said had been promised by Prime Minister Hun Sen's government. The city government resettled some families, but did not include them, they claimed.
More than 200 police had been deployed to keep watch on the protesters Wednesday. They had ordered them to stop their march to the offices, but the protesters continued, insisting they had the right because they had informed city officials of their plan.
Witnesses said riot police then hit and kicked them; nurses from a human-rights group treated the injured. Police ultimately allowed two protesters to enter the EU and World Bank offices.
No comment was available from senior police officers, who did not answer their phones.
Phan Chhun Reth, 52, whose foot was injured after being kicked by police, said she would not give up the struggle.
"I am so upset with the brutal acts of the police. Why have they beaten us, who are only women and marching peacefully to demand our land?" she said.
The protesters have said they will demonstrate all week to get attention for their cause.
The EU and World Bank did not comment.
Cambodia is largely dependent on foreign assistance for its development budget, and the EU is a major donor. The World Bank several years ago had funded a $24 million program to strengthen property rights, but to little effect.