SHANGHAI: A superstitious passenger delayed a flight from Shanghai for several hours on Tuesday (Jun 27) after throwing coins at the plane's engine for good luck, Chinese officials said.

The elderly woman was detained by police at Shanghai Pudong International Airport following the bizarre incident, forcing nearly 150 passengers to be evacuated from the plane bound for Guangzhou in southern China and causing a five-hour delay.

The 80-year-old threw nine coins at an engine of China Southern Airlines flight CZ380 as she was boarding on the tarmac.

Eight of the coins missed their target but one nestled inside an engine, airport police said, adding that a passenger spotted her and reported it to authorities.

The woman, surnamed Qiu, was travelling with her husband, daughter and son-in-law, reports said.

"A senior passenger threw coins to the plane's engine and delayed the flight. The passenger involved has been taken away by police," China Southern Airlines said in a statement on its Twitter-like Weibo account.

"In order to make sure the flight is safe, China Southern maintenance has conducted a full exam of the plane's engine."

Hundreds of thousands of Weibo users had a field day, with one commenting sarcastically: "Grandma, this is not a wish fountain with turtles."

Police at Shanghai Pudong International Airport said the woman was a devoted Buddhist and believed the coin offering would ensure her safety on the flight.

The woman will not face police action, Chinese state media reported on Wednesday.

The People's Daily newspaper, citing police, said that while she had broken the law and would normally serve five days behind bars, she is exempted because she is aged over 70.