Image copyright EPA

Korean Air has said guidelines will be revised for crew to react "firmly and actively against in-flight violence", after facing criticism for its handling of an on-board incident.

US singer Richard Marx said last week that he had intervened to help restrain a disruptive passenger on a Korean Air flight from Hanoi to Seoul.

Crew had been "ill-trained" and "ill-equipped", Marx said.

The airlines said it would also review the use of Taser guns on board.

"Korean Air will react more firmly and actively against in-flight violence that threatens the overall safety of the flight," it said in a statement.

As part of the changes, the airline said it would be providing more training to staff and hiring more male flight attendants, making sure at least one male is on duty in the cabin for each flight, according to Reuters news agency.

Marx's wife Daisy Fuentes, who was travelling with the singer, said the staff "didn't know how to use the taser" or to secure ropes.

Taser is a brand name often used to refer to electric stun guns.

Image copyright Instagram / @daisyfuentes Image caption Daisy Fuentes posted about the incident on her Instagram account

"We have decided to improve our conditions and procedure on using Taser guns to cope with violent acts and disturbances on board in a fast and efficient manner," it added, but did not elaborate on how the rules would change.

The airline said that under existing rules, stun guns were permitted for use only in "grave" situations - where the safety of a flight or the life of passengers and crew were in danger.

This meant staff had been "hesitant" to use the equipment, the carrier added.

Individual airlines have their own policies on what equipment they carry on board to restrain passengers

Most carriers contacted by the BBC were unwilling to give details of what kit this included, citing security concerns.