Photo shows the Newman Goldliner bus (plate number TXJ-710, body number 40402) which exploded along the EDSA-Buendia northbound lane at around 2 p.m. on Tuesday afternoon. (Photo credit: MMDA Twitpic)

MANILA, Philippines – A loud explosion ripped through an air-conditioned passenger bus on the busy Epifanio delos Santos Avenue (EDSA) in Makati City Tuesday afternoon, killing at least four people on board and inflicting serious injuries on at least 14 others, one of them suffered leg mutilation.

Chief Inspector Jenny Tecson, spokesperson of the Southern Police District (SPD), said two of the fatalities died on the spot while the two others succumbed to injuries, one at the Ospital ng Makati and the other one at the St. Luke’s Medical Center in Global City, Taguig City.

Tecson identified two of the fatalities as Johanson Reyes, who died on the spot, and Mariano Salustiano who succumbed to serious injuries at the Ospital ng Makati in Barangay Pembo.

An unidentified woman also died on the spot while one of the 10 victims taken to the St. Luke’s Hospital in Global City in Taguig also died.

She identified the victims taken to the Ospital ng Makati as Mabel Gozon, Mary Grace Borondian, Antonio Lino, and Jeffrey Victoriano.

Authorities were initially at a loss on what caused the loud blast, with Malacañang saying it was “a mechanical or electrical failure of some sort.”

“Definitely, it was a bomb, a big bomb,” Senior Superintendent Froilan Bonifacio, director of the Makati City Police, said later.

But Bonifacio said investigation is still being conducted on what type of improvised explosive device (IED) was used.

Director Nicanor Bartolome, chief of the National Capital Region Police Office (NCRPO), also said that the damage inflicted on the bus indicates that it was caused by an IED.

“We are still trying to determine what type of explosive material was used, we will have to complete first the investigation,” said Bartolome.

He said the IED appeared to be placed near the passenger seat located in the middle of the bus. He said that the bomb appeared to be planted at the sixth row of the passenger bus.

“The explosion occurred in the middle of the bus, it appears that it was placed at the bottom as revealed by the hole that the explosion created at the center right side of the bus,” said Bartolome.

Aside from the hole created by the explosion, the blast also damaged the windshield of the bus. A damage was also noted at the right side of the middle portion of the bus.

Chief Supt. Agrimero Cruz, spokesman of the Philippine National Police (PNP), said the explosion inside the Newman Goldliner bus, with license plate TXJ 710 and body number 40402, which was temporarily stationed at the loading bay located near the Metro Rail Transit (MRT) Buendia Station, happened at the northbound side of EDSA, at around 2 p.m. Tuesday.

The blast created monstrous traffic jam on the north-bound section of EDSA, stretching from Buendia up to Magallanes Interchange.

Bus conductor Michael Jaralbe, who sustained feet injuries, said the explosion took place minutes after two suspicious-looking men alighted from the airconditioned bus.

Jaralbe said the two unidentified men, both carrying bags, boarded the Fairview-bound bus in Baclaran and asked him if the vehicle bus will pass by Ayala. He answered yes.

But before reaching Ayala, the two unidentified men alighted.

“Both men talked to each other but I could not understand them clearly,” said Jaralbe, a native of the Visayas.

Bus driver Maximo Perigrino said he did not notice anything unusual inside the vehicle and was shocked when something exploded.

Due to the commotion, Peregrino said he stepped on the breaks and tried to open the door but it was jammed. This prompted him to smash the door glass and windshield to let the commuters out.

“I believe that the explosion was planned,” added Perigrino.

Tecson said the passenger bus came from Baclaran and heading toward Fairview in Quezon City.

“Initial investigation disclosed that the bus was traversing along EDSA bound to Fairview and prior to reaching MRT Buendia Station, the bus exploded with still unidentified type of explosive,” said Tecson.

Ed Garcia, of the Metropolitan Manila Development Authority (MMDA), said that the blast resulted in monstrous traffic jam along the northbound lane of EDSA, from the site of the explosion up to the Magallanes side of EDSA.

Bartolome said he had already ordered his men to get the statements of the survivors in order for them to have a clear idea of what happened, adding that their statements could also lead to the identification of the person or persons who planted the bomb.

The explosion is a reminiscent of the Valentine’s Day bombings in 2005 wherein three were killed while more than 50 others were injured when a bus explosion also occurred along EDSA in Makati City. Two other simultaneous explosions occurred in Davao and General Santos cities.

The extremist Abu Sayyaf Group (ASG), which reportedly maintaining links with the al-Qaeda international terror group, has claimed responsibility for the attack.

National Bureau of Investigation (NBI) Director Magtanggol Gatdula sent a team from its elite anti-terrorism division to help investigate the blast.

Gatdula said the bureau started Tuesday its parallel probe into the blast that claimed the lives of two persons and injured at least 15 persons aboard a passenger bus.

A team from the Counter Terrorism Division (CTD) headed by Head Agent Ross Bautista is now in the blast site to help police investigators.

Malacañang initially downplayed the explosion, saying it was just “a mechanical or electrical failure of some sort.”

However, upon verification, Presidential spokesperson Edwin Lacierda quickly took back his initial statement and said that the explosion was caused by “some sort of explosive device.”

Despite the explosion, Malacañang continued with the scheduled 3 p.m. testimonial at the Premier Guest House for the President's late mother, former President Corazon Aquino whose 78th birthday was commemorated Tuesday.

Vice President Jejomar C. Binay condemned the bombing as he expressed his sympathies to the victims.

He described the incident as a “deplorable and violent act.”

“Such an act should not go unpunished,” he said in a statement.

With the blast, Bartolome placed police forces in Metro Manila under the highest security alert status.

Bartolome said the move is aimed at further intensifying the security measures in Metro Manila in order to prevent the repeat of the explosion.

“We are now on full alert status,” said Bartolome in a phone interview.

Full alert status (equivalent to red alert status in the military) in the metropolis means that no policeman assigned in Metro Manila will be allowed to go on leave since the objective is to maximize the police manpower.

At the Senate, senators downplayed speculations that the bombing is a “destabilization plot” against the Aquino administration.

Senate President Juan Ponce Enrile said the bombing was not a threat to President Benigno S. Aquino III.

“Of course not. My God how can one grenade, two grenades destabilize the government. We are not that brittle,” Enrile told reporters in an ambush interview.

Sen. Gregorio Honasan also said there is not enough evidence to “point to that direction” that would support plans to undermine the present government.

“We have no evidence to support a destabilization effort. By the way, speaking about destabilization, we don’t want to convert these rising criminality into a partisan criminality issue. Because when you say destabilization effort, it means people are seriously dissatisfied with the present system,” Honasan said.

Nonetheless, Honasan urged authorities to look into the matter seriously as this could alarm even the business sector.

“This is an alarming threat, kaya concerned tayo. But ang concern natin translated into the need to amend or strengthen or make new laws to respond to this rising criminality,” Honasan added.

Sen. Juan Miguel Zubiri urged Aquino to call for a peace and order summit and also appoint a peace and order czar to fully solve the heinous crimes and acts of terrorism.

“When you get a peace and order czar let’s appoint somebody with experience, with the training, and avoid politicians for this role,” Zubiri said. (With reports from Francis T. Wakefield, JC Bello Ruiz, Jeamma E. Sabate, and Hannah L. Torregoza)