A man has died on board an Aer Lingus flight bound for Dublin, Irish police said on Sunday night. The 24-year-old was reportedly restrained after becoming agitated and biting a man about halfway through the two-hour journey from Lisbon.

Police said they were investigating after the flight was diverted to Cork when the captain declared a “medical emergency”. According to an RTE report, the man became unwell and then fell unconscious after being restrained on the flight.

It is not known exactly when he died, but police said he was pronounced dead at the scene when the aircraft landed at Cork shortly before 6pm. He was reportedly unaccompanied on the flight. RTE reported that a second man was taken to hospital and that the estimated 170 passengers and crew on board the plane were being questioned. The passengers were due to be taken to Dublin by bus on Sunday night.

Aer Lingus did not immediately respond to requests for comment.