COTABATO. The US Federal Bureau of Investigation has sent two bomb experts in North Cotobato yesterday to help investigate the bomb that exploded inside a bus Friday and injured 10 people,

The bomb went off at 2:45 p.m. inside a bus from Weena Bus Lines with body number 70-17 in Matalam town. The bus came from Cotabato City and was en route to Davao City. The injured, mostly bystanders, were immediately taken to Armas Provincial Hospital.

According to Inspector Elias Colo, Police Chief of Matalam, the American experts would help determine if the terrorist group Jemaah Islamiyah was involved in the attack.

The report said the FBI bomb experts were also involved in recent military exercises between the US and Philippines held in Carmen, Cotabato.

Maj. Gen. Raymundo Ferrer, Army's 6th Infantry Division chief, said Friday the bombing may be related to the May 18 bombing of the Weena Bus Lines terminal in Cotabato City. The military has discounted the possibility that terrorists were behind the bombing and said extortion may have been the probable motive.

Agence France Presse (AFP) reported that a police official said the explosion was believed to have been set off by a mobile telephone. The explosion came despite tight security in the region. Seven policemen were posted at the bus station amid warnings of a possible terror attack in the region.

Police, however, suspect the bombing was carried out by militants who have been trained by members of the Southeast Asian terror group Jemaah Islamiyah (JI), AFP reported. Two JI leaders, Indonesian nationals Dulmatin and Umar Patek, alleged bombmakers responsible for the deadly 2002 Bali bombings, are thought to be hiding with local guerrillas in the southern Philippines.