An elderly woman in China created panic at the Shanghai Pudong International Airport on Tuesday (27 June) after she threw coins into a plane's engine while boarding.

Her act to bring "good luck" led to a five-hour delay, China Southern Airlines reportedly said through their official WeChat account. The plane was flying from Shanghai to Guangzhou.

Had the engine sucked up the coins, it could have been disastrous as the metal could have damaged the machine, the captain of the flight was quoted as telling reporters by the South China Morning Post.

Airport maintenance crew recovered nine coins from one of the engines. They were alerted by fellow passengers who saw the woman, believed to be in her eighties, throwing something into the engine. She was flying with her husband, daughter and son-in-law.

The airport said an investigation was being conducted into the incident and the woman was being questioned. She reportedly told the police that she threw the coins into the engine to pray for the safety of the flight. Throwing coins into rivers and waterfalls is considered to bring good luck in several countries across the world.

"After an investigation the involved passenger, surnamed Qiu, said she threw the coins to pray for safety. According to Qiu's neighbour, Qiu believes in Buddhism," the police were quoted by the BBC as saying.

After a green signal from the airport staff, the flight finally took off at 5.52pm local time (10.52am BST), five hours after its scheduled departure.

There have been several incidents in the past years in China where airline passengers have violated safety rules and put flights at risk, including opening emergency doors and assaulting cabin crew members.

China Southern Airlines urged all its passengers to comply with civil aviation laws and regulations, and also to avoid behaviour that could prove detrimental to passenger and flight safety.