Police said Saturday they were investigating the possible involvement of two politicians in the bombing of a provincial airport in the south that left two people dead. “We requested our partners from the Armed Forces of the Philippines and other intelligence agencies to conduct manhunt operations against the (politicians),” national police chief Jesus Verzosa told reporters. The “human bomb” attack on Zamboanga airport may have been linked to a failed assassination attempt last year on Gov. Sakur Tan of nearby Sulu province, Verzosa added. Tan was among 24 people injured Thursday when a man carrying a backpack loaded with explosives and another man were killed in a blast outside the passenger terminal shortly after Tan had stepped off a plane. Verzosa said police want to question three people including two of Tan's political rivals, Temogen Tulawie, known by his nickname Cocoy, and Moamar Askali. All three were at large after they were indicted along with two other suspects in the assassination attempt against Tan on May 13 last year in which four of the governor's bodyguards were wounded, the police chief said. Tulawie and Askali belong to Sulu families that have contested local elections against Tan. President Benigno Aquino III Saturday also ordered the national police to beef up airport and seaport security to prevent a possible recurrence of Thursday's explosion at the Zamboanga International Airport. “Malacanang has issued a directive to secure airports and seaports. So we are beefing up security at airports and seaports,” national police spokesman Senior Superintendent Agrimero Cruz Jr. said in a radio interview. He said security is being strengthened while authorities are verifying whether the blast was a suicide bombing attempt. He said the police has started deploying personnel from its Aviation Security and Maritime Groups to secure major airports and seaports across the country. The incident prompted the United Kingdom to issue a travel advisory warning British nationals against traveling to any parts of Mindanao. Earlier, Zamboanga City Mayor Celso Lobregat said initial investigation showed that a man carrying explosives on his back may have been responsible for the attack. “Investigators have yet to find the triggering device. The bomb was placed at the back of the suspected bomber, probably inside a backpack,” the mayor said. Zamboanga City police chief Senior Superintendent Edwin de Ocampo identified the man as Reynaldo Apelado based from identification cards found in his body which was badly mangled in the explosion. “He is a mason and has no relatives in the city. We are checking his background,” De Ocampo said in a radio interview. Police officials said the bombing incident could not have been a terrorist attack since there was no shrapnel in the wounds suffered by the victims. If the explosive was prepared by terrorists, they could have loaded it with shrapnel for a move devastating effect, the officials said. Military spokesperson Brig. Gen. Jose Mabanta also ruled out suicide bombing in the incident. “The possibility of him (Apelado) being a suicide bomber is highly improbable but of course this still has to be verified. From all angles, we look at it as almost impossible, highly improbable that the perpetrator is a suicide bomber,” he said. De Ocampo said the bomber appeared to have a target in mind. Prior to the explosion, the suspect had positioned himself near the area where Sulu Gov. Abdusakur Tan would pass on the way out of the airport, he said. Tan said he could have been the target of the bombing. But Loberegat said this has not been established yet. He also denied reports that there were security lapses at the airport, saying the explosion occurred outside the airport premises. “If the explosion occurred inside the terminal I would say there was a security lapse. But this happened outside the arrival area,” Lobregat said.