MANILA - Six suspected drug traffickers, including three Koreans, exported shabu to South Korea and the United States from their condominium in Makati City using ordinary expandable folders, police said Wednesday.

Quezon City Police District chief Senior Supt. Guillermo Eleazar said the group would make hidden flaps inside the folders where they could insert customized plastic sachets containing drugs.

"Ang nakalagay po doong mga shabu ay 2 grams for each sachet na mahaba. Durog na durog po iyun kaya maglalaman po ng apat na sachet doon po sa palibot ng folder na iyun," Eleazar said.

"Kapag iyun po ay idinikit na, hindi niyo malalaman na may sachet po ng shabu doon."

[Each sachet contains 2 grams of shabu. These are pulverized so each folder can carry four sachets. When the flaps are already closed, you won't suspect that there are sachets of shabu there.]

The suspects, he said, also packed magazines or documents inside the folders before sending them to the US and South Korea via courier service.

The six suspects -- three Koreans and three Filipinos -- were arrested Tuesday during a buy-bust operation at their upscale condominium unit in One Rockwell East Tower, Makati City.

Look: Mugshot ng anim na naarestong suspek kabilang ang tatlong koreano sa Makati. Sa Korea at USA umano naipapadala ang mga iligal na droga pic.twitter.com/EBDmGIH0Tt

— doland castro (@dolandcastro) November 1, 2016

Eleazar said the group had refused to open their unit for about 15 minutes, forcing policemen to break down the door. An operative was injured after one of the suspects stabbed him with a katana as he barged into the room.

Confiscated from the suspects were sachets of suspected shabu, five guns, four samurai swords, two laptops and 10 cellphones.

Naaresto ang 3 Koreano sa condominium unit sa Rockwell East Tower sa Makati City. Iba't ibang drug paraphernalia, nakumpiska. pic.twitter.com/RZqmnsR8XQ

— jeff hernaez (@jeffreyhernaez) November 1, 2016

The suspects may have flushed the rest of of the drugs down the toilet while police were struggling to enter the condo unit, Eleazar said.

The QCPD, he added, has coordinated with the Korean Embassy to verify the claim on one suspect who introduced himself as an intelligence officer.

The police Anti-Cybercrime Group is also trying to get more information on the underground operation through the confiscated laptops and cellphones.

The suspects will face charges of violating the Comprehensive Drugs Act of 2002 and the Comprehensive Firearms and Ammunition Regulation Act, among others.