Article published on the 2008-09-01 Latest update 2008-09-01 12:09 TU
The police said that the blast was caused by a home-made bomb. Four people instantly, while another died in hospital shortly afterwards.
Police have set up roadblocks around the city of Digos to catch the perpetrators after they fled the scene of the explosion.
No-one has claimed responsibility, though the police had warned the public of possible attacks following a recent military offensive on Mindanao Island, against guerillas from the Moro Islamic Liberation Front (MILF).
Police say that they are also investigating the possibility that the attack was the work of organized crime. The bus firm, Metro Shuttle, had received threats after refusing to pay protection money to the Al-Khobhar gang. This group is suspected of being responsible for another bomb attack on a Metro Shuttle bus last month. That attack, also in Digos, killed three people.