Gunmen wearing police uniforms stopped a passenger bus in the southern Philippines early on August 26 and shot dead four people, including two police officers, say officials.

The attack came just three days after a local ex-policeman took a busload of Hong Kong tourists hostage in Manila , killing eight of them before being shot dead by a police sniper.

The bus was travelling from Cagayan de Oro to Zamboanga City in the southern Philippines , where Muslim rebels and criminal gangs operate, said Orlando Vinas, the Lanao del Norte provincial police chief.

The gunmen ordered the passengers to get off at a road checkpoint and shot four people, including the two uniformed police marshals, the driver and the bus conductor. They then burnt the bus.

No organisation or individuals have taken responsibility for the attack.

Vinas said that the marshals were deployed on regional buses plying the same highway after gunmen held up a bus to extort money from passengers earlier this month./.