Cambodian authorities have implemented a brutal crackdown on dissent a day after four people were shot dead during a protest by striking garment workers.
In a sign that strongman prime minister Hun Sen has hardened the government's response to opposition and labor protests, police were joined by unidentified men carrying steel pipes as they forced opposition supporters from their rally base in Phnom Penh on Saturday.
Monks and women were among those chased and beaten.
The government has banned all rallies and marches through the streets of the capital, citing security reasons.
The country's Defence Ministry took the unusual step on Saturday of issuing a statement affirming the military's loyalty to the government, the king and constitution.
The ministry said the armed forces blamed "opportunists" and politicians who had insulted the government and incited people to oppose Mr Hun Sen's leadership by provoking instability.
Government officials denied rumors sweeping social media that key opposition and labor figures were to be arrested, including opposition leader Sam Rainsy who returned to the country days before last July's disputed national elections.
After initially declaring a major protest would go ahead on Sunday despite the violence Mr Rainsy's party called off the rally, fearing more people would be killed.
The turn-out was expected to be larger than other protests since the elections because of anger over military police opening fire on garment workers who are demanding a doubling of the minimum wage.
The local human rights group LICADHO described Friday's clash as the "worst state violence against civilians in Cambodia in 15 years."
The United Nations special rapporteur Surya Subedi has called for an investigation into whether excessive force was used.
Lang Rith, a 29 year-old demonstrator from southern Takeo province, said he was hit with a baton on his back on Saturday as he tried to run away from Freedom Park which was a base for the protest movement since December 15.
"They beat us like they beat animals. I am very scared," Lang Rith told Associated Press.
Protests have grown in recent weeks as garment workers joined opposition supporters demanding a re-run of the election the opposition claims was rigged to allow long-serving Mr Hun Sun to remain in power.
The decision to force protesters from Freedom Park came after the collapse of planned talks between the government and opposition leaders.
Until Friday Cambodian authorities had shown restraint in handling the protests while Mr Hun Sen remained firmly in control of the police and military.
A former cadre of the murderous Khmer Rouge who defected to Vietnam before becoming Asia's youngest leader three decades ago, Mr Hun has shown in the past he is capable of instigating violence, as in a 1997 putsch that overthrew his then senior coalition partner Prince Norodom Ranariddh.
- Sydney Morning Herald