Valera and Luna are pitted against each other in the race for Abra’s lone congressional district.
Luna has openly tagged Valera in the killing of her supporters, which the governor has denied. She also implicated him in a previous attempt on her life.
Citing reports reaching his office, Valera said what happened was "either a misencounter or a legitimate encounter between government troops – either the police or Army – and a group of civilians, who happened to be (members) of the PAG (private armed group) of Mayor Luna."
He asked the National Bureau of Investigation (NBI) to thoroughly probe the incident and the background of the victims.
He also cited reports that M-16 and M-14 rifles were found in the Mitsubishi Pajero carrying the victims. Luna owns the vehicle.
"What can I gain politically if I would order the killing of the six men who were ambushed. Luna neither has a political value nor is a threat to my political career," Valera said.
He said Lagayan town has only more than 2,000 voters.
Besides Valera and Luna, two others are running for Abra congressman – lawyer Gil Valera and Mailed Molina, head of the Cordillera People’s Liberation Army.
Luna earlier said that only Valera has the motive and capability of staging the ambush which she said targeted her. Three others were wounded in the attack at the boundary of Barangays Pang-ot and Bai in Lagayan town.
"Ako talaga ang puntirya niyang patayin (I’m the one who he was targeting to kill)," Luna was quoted as saying.
Valera said Luna, who was not in another town during the ambush, was just eliciting sympathy to gain votes.
Senior Superintendent Alex Pumecha, Abra police director, however, said they have no evidence to link Valera to the ambush.
Police earlier expressed suspicion that one of the seven active PAGs in Abra pulled off the ambush.
Abra, which is part of the Cordillera Administrative Region, has been placed under the control of the Commission on Elections because of its history of poll-related violence.
Last December, Abra Rep. Luis Bersamin was gunned down in front of the Mt. Carmel Church in Quezon City. Valera was also tagged in the gunslaying but he belied the accusations.
Valera’s wife is running for governor against Bersamin’s brother Eustaquio.