The three men presented at the national police headquarters in Manila were said to be members of an extortion gang, Urban Lions Group, in Kidapawan in the province of North Cotabato.

The group's alleged mastermind, Datu Mamintal, yielded to the military in Carmen town in the province earlier this week while the other two were arrested in separate raids in Kidapawan, police officials said.

Authorities have offered a reward of one million pesos (about 19,000 US dollars) for the capture of those responsible for the bomb blast inside the Weena Bus terminal on Oct. 10 that also left more than 20 people wounded.

The owner of the bus company said earlier that prior to the bombing, the group had demanded four million pesos (about 75,000 dollars) from the company several times but was repeatedly ignored.

The country has been hit by a wave of bomb attacks in this month, in which at least 20 people have been killed and more than 200 others wounded.

President Arroyo summoned her cabinet, top military and police officials and local government executives of Metro Manila for a closed-door meeting at the presidential palace on Saturday morningto discuss security measures.

On Oct. 2, a powerful bomb exploded in front of a bar near a military camp in the southern city of Zamboanga, killing one US soldier and three local civilians and wounding over 20 others, including a second American serviceman.

On Thursday this week, another seven people were killed and some 150 injured in the city when two bombs blasted in two shopping malls. Police also found and defused at least seven bombs at other places in the city.

Only 12 hours after the twin bombing attacks in Zamboanga, a grenade exploded atop a flyover in the financial district of Makati in Metro Manila shortly after midnight Thursday, in which no one was injured.

Then came another deadly bomb explosion inside a packed bus in Quezon in the capital area on Friday night, killing two persons, not three as earlier reported, and wounding 20 more. Police said Saturday they have a description by a witness of a man suspected of planting the bomb on the bus.

President Arroyo said Friday that authorities have already identified four suspects of Thursday's bombings in Zamboanga, but declined to confirm their identities. The military has said the prime suspect is the Abu Sayyaf group, allegedly linked to the al-Qaeda network of Osama bin Laden.

(Xinhua News Agency October 19, 2002)