Killed in the incident were NBI special investigator Teddy Colcoli, NBI informers Daniel Domingo, 18, and Soledad Guzman, 45; and suspected drug dealer Alvin Bantuas.
Colcoli was with the NBI dangerous drugs division while Guzman and Domingo were allegedly NBI "assets" based in Batangas.
According to the NBI, the sting operation involved 16 agents with Colcoli posing as a taxi driver while Domingo and Guzman posed as passengers. Another NBI agent, Geonel Aperio, hid in the trunk as backup.
On Monday, Colcoli, Guzman and Domingo who posed as buyers met Bantuas, his henchman Tata Gabby and a certain Lomu in Zapote, Las Piñas City to arrange the purchase of a kilo of shabu for P600,000.
Bantuas supposedly told Colcoli and the two agents to go to his house at Block 38, Baker Street, Fairmont Subdivision in Fairview, Quezon City on Wednesday to conclude the deal.
On Wednesday, Colcoli and his informants, backed up by 16 other agents, arrived at the appointed place and parked in front of Bantuas house at around 10 p.m. where Bantuas was waiting for them.
When Bantuas boarded the cab, he demanded to see the money for the shabu and Guzman and Domingo showed him the P600,000 in marked cash.
After seeing the cash, Bantuas signaled a certain Abolkhier Calandeda, one of his henchmen, but Colcoli sensed something amiss and drew his gun but Calandeda reportedly grappled with him for it.
The gun went off during the scuffle, wounding Colcoli and Bantuas. They were rushed to a nearby hospital but died along the way, the NBI said.
Bantuas unidentified henchmen then dragged Guzman and Domingo inside Bantuas house and shot them in the head.
Aperio, who was locked inside the cabs trunk, then called NBI senior agent Regner Peneza to move in but the suspects had already fled with the P600,000 marked money.
Meanwhile, sketchy reports said Calandeda was killed by NBI agents as he tried to escape the authorities in a follow-up operation in Pasay City early yesterday morning.
The NBI said five more suspects were also rounded up for questioning in another follow-up operation in North Fairview Subdivision in Quezon City.
Sources identified those detained for questioning at NBI headquarters as a certain Ali Dicampong, his brother Jamal, Minsuari Macarambong, Ali Maisa and Pacalma Rascal.
The suspects denied they were part of Bantuas drug ring and claimed they were just vendors at the market area at Manggahan along Commonwealth Avenue in Quezon City.
NBI officer-in-charge Lolito Utitco meanwhile ordered a bulletin against other suspects who are now suspected to be fleeing to Mindanao.