
Worried that the man may try to do harm after he refused to talk to anyone, the pilot sought permission to land at Suvarnnabhumi Airport, said Don Muang Airport director Anirut Thanomkullabutr during a press conference.
The Thai Aviation Authority, however, rejected the request, ordering the aircraft to land at Don Muang Airport instead.
Thai police then boarded the aircraft and arrested a Bangladeshi man identified as Harun Orachid Hasan Ali, 23. He was on his way back to his hometown after being arrested in Malaysia for illegally working in Kuala Lumpur.
Speaking at the same press conference, Air Marshal Chana Yusathapon said that the Don Muang aviation tower was alerted at about 9.15am from the GMG 042 airline flight from Kuala Lumpur that a passenger was acting suspiciously.
Chana said that after the aircraft landed, police arrested the suspect without using force.
Police also searched luggage of the suspect but found no weapons.
Chana added that the Thai side ordered the landing to take place at Don Muang which is not as crowded as Suvaranabhumi.
"If the situation turns bad and we have to use weapons, Don Muang Airport which is not crowded is the better place," he said.
He added that the Thai side has contacted Bangladesh Embassy officials about the suspect who will be deported to Bangladesh soon.
The Thai authorities will seek an investigation in Malaysia about why the suspect was able to carry a knife on board.