At least three people were injured when a bomb ripped through a bus in the restive southern Philippines on Monday, the military said.
The "improvised explosive device" went off aboard the bus as it was travelling through the southern town of Kabacan in North Cotabato province around noon, said regional army spokesman Major Randolph Cabangbang.
"At least three people were wounded," Cabangbang said.
No one has claimed responsibility for the attack, although previous bus bombings have been blamed on Muslim armed gangs extorting money from transport operators.
Kabacan is on Mindanao island, where Muslim separatist rebels have been waging a rebellion since the late 1970s. Many former guerrillas are known to have resorted to banditry over the years, police say.