A 19-year-old under investigation for attempting to open an emergency door during flight has admitted that he had taken methamphetamine days before the incident, police said Friday.

The unnamed teenager, who tried to open the airplane door in a flight from the Philippines to Incheon, said he took drugs with six Filipinos at a hotel in Cebu two days before the flight. He has since been questioned by the Incheon Airport Police.

The suspect was on the Jeju Air flight that departed from Mactan-Cebu International Airport on June 19.

During the flight, he said he “would kill everyone by opening the door” and argued with the flight attendants when they tried to move his seat, issuing threats with a pen at one point, according to witness testimonies.

When asked later about the incidents by local reporters, he said that he “felt like being attacked by those in power.” He did not elaborate further, and did not provide a clear motive for his actions when questioned by police.

He was taken into custody moments after landing, and tested positive on a rapid drug test.

The prosecution has requested a detailed examination of his samples to the National Forensic Service, for which they are currently awaiting a result. If drug use is confirmed, officials plan to conduct an investigation on how he acquired the substance.

The incident had caused a scare for the South Korean public after a similar incident occurred last month.

On May 26, a 33-year-old surnamed Lee forcibly opened a door during an Asiana Air flight from Jeju Island to Daegu. No severe injury occurred as the incident took place when the plane was at low altitude -- 200 meters above ground -- but 12 passengers had minor issues including nausea and trouble breathing. The damage to the plane was estimated to be 640 million won ($485,000).

Lee was charged for property damage and violation of the Aviation Security Act.