Investigators are now preparing artist’s sketches of the bombers based on the witnesses’ descriptions. Police and local authorities have offered P100,000 reward for the arrest of the perpetrators.
Philippine National Police chief Director General Arturo Lomibao said initial findings showed that "it could probably be extortion."
Lomibao, who was here for a series of meetings with police officials in Southern Mindanao, personally assessed the investigation of Task Force Weena.
He said the New People’s Army (NPA), which marked its 37th anniversary Wednesday, did not have a hand in the bombing of the Weena bus.
"It had nothing to do with the (37th) NPA anniversary," he said.
The Weena bus company, which plies the routes from Davao City to parts of Central Mindanao, has suffered similar attacks in the past years, largely blamed on extortion syndicates.
More than a dozen Weena buses have reportedly been bombed since 2003.
"The owner of the bus company told me that he received a call that one of our buses would be bombed, without elaborating," Junaid Adam, manager of Weena’s Cotabato City office, told The STAR.
Adam said 17 people (not 22 as earlier reported) — 10 of the 21 passengers and seven bystanders — were wounded in Wednesday’s blast that tore off the roof of bus number 26 and damaged two other buses parked nearby.
Davao City Mayor Rodrigo Duterte, who chairs the Regional Peace and Order Council, said he would go by the results of the police investigation into the explosion.
"But we have also put in place all the necessary security measures in the region," he said, adding that an "orange" alert is now in effect. — With Edith Regalado and John Unson