Authorities in the US state of Massachusetts arrested a man after he tried to open an emergency exit door on his United Airlines flight while the plane was in the air, prosecutors said on Monday.

When the 33-year-old suspect began attacking flight attendants, other passengers managed to tackle and help restrain him until the plane landed safely in Boston.

"No serious injuries were reported," the airline said in a statement.

What is the man accused of?

The incident took place on a cross-country flight from Los Angeles to Boston on Sunday, the US Attorney's Office for Massachusetts said in a statement.

Less than an hour before the plane was due to land at Boston Logan International Airport, the flight crew were alerted that a side door had been disarmed.

A flight attendant inspected the door and found that the locking handle had been moved from the fully locked position, and that lever for the door's emergency slide had been disarmed. The crew then secured both the slide and the door.

The flight crew suspected the 33-year-old passenger of tampering with the door, as he had been seen standing near it for a period of time. Crew members alerted the captain that the passenger likely "posed a threat to the aircraft."

Prosecutors said that at that point, the suspect got out of his seat and attacked one of the crew with a broken metal spoon, "hitting the flight attendant on the neck area three times."

Other passengers then tackled the man and helped crew members restrain him until landing.

How has the airline reacted?

United Airlines said that the passenger will be barred from any future flights with the carrier.

"We have zero tolerance for any type of violence on our flights, and this customer will be banned from flying on United pending an investigation," the airline said.

The man has been charged with attempted interference with flight crew members and attendants using a weapon.

Life sentence is possible

If he is found guilty, the 33-year-old could face a potential life sentence in prison.

Despite the alleged attempt, airplane doors cannot be opened during the flight due to cabin pressure.

US sees series of airplane safety incidents

In a separate incident on Monday, two United Airlines flights bumped into one another at Boston Logan Airport.

While one of the airplanes was being pushed back from its gate, the jet's wing struck the tail of a neighboring United flight.

No injuries were reported and all passengers disembarked. Both planes have been taken out of operation for the time being. The Federal Aviation Administration (FAA) said it has launched a probe into the incident.

It is the latest in a series of safety incidents involving passenger aircraft in the US — and the second involving Boston's international airport.

Last week, a JetBlue flight attempting to land at Boston's airport was forced to take evasive measures when a charter jet crossed an intersecting runway.