Investigators trying to determine if the attackers were from the same armed group that had staged similar bombings in past years to extort money COTABATO, Philippines: A homemade bomb went off in a bus and killed a passenger and wounded 10 others in a southern Philippine city on Sunday in an attack authorities suspect may be part of an extortion attempt, officials said. The bus with an unspecified number of passengers was approaching a transport terminal in Tacurong city in Sultan Kudarat province when the bomb went off at the back of the vehicle shortly before noon, police said. Investigators were trying to determine if the attackers were from the same armed group that had staged similar bombings in past years to extort money from the Yellow Bus Line, which operates in key southern cities, military and police officials said. Regional army commander Maj. Gen. Roy Galido said the bus company “has been constantly receiving extortion messages.” The military and police have been working with the bus owners to capture the extortionists, who may have been angered by the bus company’s refusal to pay off, Galido said. Police have blamed the Bangsamoro Islamic Freedom Fighters, a small rebel force that has aligned itself with the Daesh group, for similar bus bombings in the past. The group broke off years ago from the Moro Islamic Liberation Front when the latter entered into peace talks with the government and embraced an offer of Muslim autonomy in a five-province region in the south of the largely Roman Catholic nation.