An improvised explosive detonated on a bus Thursday in the southern Philippines, killing nine people and injuring 20 others, officials said.The blast took place Thursday morning on the Kabacan-Matalam national highway in the town of Matalam in North Cotabato, on the island of Mindanao.The bus driver was among those instantly killed, said regional police director Gil Meneses.Extortion was a possible motive for the attack, Meneses said.Bus companies serving the Cotabato-Cagayan highway have received extortion threats from various groups, the state-run Philippine News Agency said. There have been previous attacks on buses, killing or injuring dozens. The groups Abu Sofia and the Al-Khobar, both linked to the separatist Muslim group Abu Sayyaf, were blamed for the previous attacks.The province of North Cotabato is just to the east of Maguindanao, the site of what is considered the worst politically motivated violence in recent Philippine history.
In November 2009, at least 57 people were killed when their convoy was ambushed in Maguindanao. The former mayor of the province is accused of plotting the deaths to thwart a political rival.Maguindanao is part of an autonomous region in predominantly Muslim Mindanao, which was set up in the 1990s to quell armed uprisings by people seeking an independent Muslim homeland in the Philippines, a predominantly Christian country. – Cnn