MANCHESTER, England, May 7 (UPI) -- Passengers on an England-to-Paris Air France flight say a near-collision with another aircraft was the result of the pilot showing off for a young boy.

The passengers said the pilot allowed a young boy to enter the cockpit -- a practice banned in Britain since the Sept. 11, 2001, terror attacks in the United States -- and purposefully caused the Airbus A320 to rock from side to side during a Saturday flight from Manchester to Paris, the Daily Mail reported Wednesday.

"I was horrified by what I saw," said passenger Shaun Robinson, 40, who runs the travel Web site www.holidayinsider.com. "The pilot made a sharp turn to the left, without warning, and then back again, obviously showing the young French boy how he flew his plane."

Robinson and other passengers on the jetliner, which had 143 people aboard, said alarm noises began emanating from the cockpit shortly after the boy returned to his seat.

"(The pilot) said air traffic control had come on the radio and said 'climb, climb, climb 10,000 feet, you are going to hit a plane.' It was terrifying. People were blessing themselves. Perhaps the pilot lost concentration and took his eye off the ball," Robinson said.

An Air France spokesman said the incident was under investigation.