Police said Thursday that an unemployed South Korean man admitted to have left a suspicious box at South Korea's main airport in anger over his unemployment.

The 36-year-old told police that he made the box at his home using a butane gas canister and installed it in a bathroom at Incheon International Airport.

"I made the box based on what I have seen in movies before," he was quoted by police as saying.

He is being questioned by police after he was apprehended on Wednesday night at his home in Guro, southwestern Seoul.

The box found last Friday contained a warning message in Arabic, a butane gas canister, one bottled water and guitar strings, as well as broccoli and a banana peel, police said, noting no explosives or detonators were found.

The message, written in Arabic on half an A4-size sheet of paper, read: "This is the last warning to you. God will punish." 

He told police that he printed the threatening message using Google's translation service tool and that he had no intention of making an actual explosion.

The suspect, who graduated from graduate school majoring in music, said he was discontent with the society as he could not get a job and was in need of money, according to police.

The suspect has a newborn with his wife whom he married a couple of years ago, according to police. He has neither a criminal record nor history of mental illness.

After analyzing the note, police had concluded that the possibility of a Muslim terror organization's involvement was rather low.

Experts have said there are some grammatical errors and it is different from typical threatening messages, which either cite the Koran or are written in the name of Allah.

Police said they will request a formal arrest warrant later on the day, after investigating the details of the incident and possible involvement of a terrorist organization. (Yonhap)