(UPDATE) 11 killed, 21 injured in Bukidnon blast

MANILA, Philippines (Xinhua) - At least 11 people were killed and 21 other were injured when an improvised bomb ripped through a passenger bus in Bukidnon this afternoon, the military said.

A Rural Transit bus was at the vicinity of Central Mindanao University in barangay Muswan in Maramag town when the bomb exploded at around 5:45 p.m., according to Christian Uy, public affairs officer of the Army's 4th Infantry Division.

He said of the nine fatalities, five were male and four were female. The 17 injured people were taken to the hospital for treatment.

A military official who declined to be named said the explosion occurred shortly after a group of students boarded the bus.

Uy said the authorities have started investigating as to the people or group responsible for the explosion but it's too early to tell who are the suspects.

In November, three people were hurt when a bomb exploded in a passenger bus from the same company in Maramag town.