Cambodian security forces briefly clashed with dozens of protesters on a street, just east of Freedom Park, here on Monday morning, leaving one protester injured on head, a human rights activist said.

The clash broke out when protesters tried to remove barricades to enter the Freedom Park but were prevented by security forces, Am Sam Ath, a senior investigator for the rights group Licadho, who observed the incident, said after the event.

"As dozens of protesters had tried to enter the park, but security forces had prevented and fought them with batons. As a result, one protester sustained head injury," he said.

National Military Police spokesman Gen. Kheng Tito confirmed the incident, saying that the group staged an illegal protest that could cause social disorder.

"The country has its own law, they cannot do anything in violation of the law," he said. "Our security forces just enforce the law so as to maintain social security and public order. "

The incident happened after Mam Sonando, owner of the opposition-aligned Beehive Radio station, and about 70 of his supporters defied a government ban on the rally.

The group protested against the Ministry of Information for repeatedly rejecting a Mam Sonando's request for a relay radio station and a TV station.

Many rallies and demonstrations have been held by the country's main opposition Cambodia National Rescue Party (CNRP) and its aligned trade unions and associations since the disputed election in July last year.

The poll results showed that Prime Minister Hun Sen's ruling party won 68 parliamentary seats and the Sam Rainsy's opposition CNRP got the remaining 55 seats.

Claiming serious irregularities, the opposition refused to accept the outcome and has boycotted parliament and held protests in order to demand the resignation of Hun Sen and a re-election.

Hun Sen has said that he would neither step down nor call a re- vote.