At least two people have been killed in a bus bombing in the southern Philippines, military officials said.

Five others were injured in the attack, which happened as the bus pulled into Carmen on the island of Mindanao.

Regional military commander Col Leopoldo Galon told the Associated Press that extortion gangs linked to Muslim rebels have been responsible for similar attacks in the past.

The island of Mindanao is home to a long-running Muslim insurgency.

Earlier reports said that 10 people had been killed and two wounded, but a military official told AFP news agency the casualty figures were amended after soldiers reached the scene.

The southern Philippines has a long history of conflict, and Muslim groups have been fighting for independence in the area for more than 30 years.