PHNOM PENH • Premier Hun Sen has called on security forces to strengthen their loyalty to the current government, and asked them to immediately take measures against any political group attempting to topple the "legitimate" regime.

He made the remarks in a speech on Thursday to some 5,000 senior military and police officials at the headquarters of the Prime Minister's bodyguard unit in Takhmao town in Kandal province, reported The Phnom Penh Post newspaper.

"The armed forces must be loyal to the government and have to prevent any act of colour revolution," a member of the armed forces quoted Mr Hun Sen as saying. The PM also warned that opposition lawmakers causing problems over the country's disputed border with Vietnam would be clapped in irons, regardless of parliamentary immunity.

A group of opposition lawmakers from the Cambodia National Rescue Party, along with more than a thousand supporters, went near the border in Svay Rieng province last month to investigate reported encroachment by Vietnam. They clashed with Vietnamese security personnel and ten people were hurt.

"The Premier said it was lucky the rival group who had provoked issues at the border hadn't caused any serious disaster," the Post's source said.

Mr Sok Eysan, a spokesman for Mr Hun Sen's ruling Cambodian People's Party, described the Premier's remarks as a "routine instructional speech" about the responsibility of the armed forces. Mr Hun Sen advised the armed forces how to peacefully cooperate with Cambodia's neighbours, he added.