MANILA (UPDATE) - Justice Secretary Menardo Guevarra on Tuesday ordered the National Bureau of Investigation (NBI) to look into the killing of Calbayog City Mayor Ronaldo Aquino and 4 others.

The Philippine National Police said Aquino, his police escort, and driver were killed on Monday afternoon in an alleged shootout with policemen, which Samar 1st District Rep. Edgar Mary Sarmiento refuted.

Two policemen who supposedly exchanged gunfire with the camp of Aquino also died, added the PNP.

• 'Bakit naka-bonnet, M-203?' Calbayog mayor's slay an ambush, says lawmaker
• Calbayog City mayor's vehicle ambushed; 3 dead, 1 in critical condition - PNP

Under Department of Justice Order No. 57, NBI officer-in-charge Eric Distor is "directed to submit reports on the progress of the subject investigation directly to the Office of the Secretary within 10 days."

The same order authorized the NBI to "file the appropriate charges against all persons involved and found responsible for any unlawful act" in connection with the case "if evidence warrants."

JUST IN: Justice Sec Menardo Guevarra officially orders NBI to probe killing of Calbayog City Mayor Ronaldo Aquino and other persons yesterday. pic.twitter.com/FAaZbyJ8PF

— Mike Navallo (@mikenavallo) March 9, 2021

"Ire-refer namin sa NBI for the simple reason na ang other party involved ay PNP. 'Yun ang na-gather naming information, na ang naka-engkuwentro allegedly ay police officers," Guevarra told reporters.

(We will refer this to the NBI for the simple reason that the other party involved is the PNP. That's the information we gathered, that the mayor had an armed encounter with alleged police officers.)

"So magkakaibang version 'yan. So siyempre, para objective and impartial investigation, I will direct the NBI today to investigate the incident."

(There are different versions. So in order to ensure objective and impartial investigation, I will direct the NBI today to investigate the incident.)

Police shot first at the mayor's vehicle, Sarmiento said, citing witnesses.

"Doon naman sa mga nang-ambush, masakit sabihin kaya lang mga naka-uniporme ito, mga miyembro pa ng PNP. Akoy nagtataka bakit naka-bonnet at saka naka-M-203 pa. Talagang handang-handa," he told ABS-CBN's TeleRadyo.

(To those who conducted the ambush, it is painful to say but they were in uniform, they were members of the PNP. I am wondering why they were wearing bonnet and using M-203. It was all planned.)

But according to a statement from the PNP Public Information Office, "the group of Mayor Aquino was alleged to have initiated the shootout when his close-in security fired at the unmarked vehicle of the IMEG-PDEU group that was traveling in the same direction along the road."

The PNP said its personnel involved in the shooting are from the Integrity Monitoring and Enforcement Group, and Provincial Drug Enforcement Unit, who were conducting Red Teaming inspection in the area.

"The IMEG-PDEU group denies that Mayor Aquino was a subject of their operations or that he was targeted," the PNP statement said.

A Special Investigation Task Group created by the PNP Eastern Visayas will confirm the veracity of that statement.

The PNP-PIO said other police personnel involved in the incident "claimed they were initially unaware of the passengers on board the vehicle that fired up on them" and only learned after the firefight that the vehicle is owned by Aquino. This will also be validated by the SITG, it added.

Aside from the 5 fatalities, a civilian employee from Aquino's camp, and one personnel from the PNP side were wounded during the incident, said the PNP.

Malacanang condemned the incident, with Presidential spokesman Harry Roque expressing alarm as, according to him, it may be the start of killings due to politics as elections near.

"We condemn that because the right to life is the most important right," he said.

• READ: Shootout or ambush? Palace raises alarm on Calbayog mayor's slay

Vice President Leni Robredo noted that the killing of Aquino came a day after the "massacre of community organizers in Calabarzon."

"Dalangin at panawagan ko ang pagkagising ng ating bansa. Hindi normal ang pagpaslang na ito," she said in a statement.

(I pray and appeal for our country to wake up. This killing is not normal.)

"It should not be treated as normal that mayors, community organizers, lawyers, judges, journalists, children, and even victims of the drug trade are outright murdered in our streets or in their homes. We must connect the dots between these gruesome deaths and see the web that enables and emboldens these killings: Impunity, the normalization and incitement of violence, and the kill, kill, kill rhetoric coming from the highest offices," Robredo said.

"We call for a clean, competent, and independent investigation into Mayor Ronaldo Aquino's death, and for his murderers to be brought to justice," she added.

--Report from Mike Navallo, ABS-CBN News

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