Even a quick moment of carelessness can cost airline passengers their portable luggage, as thieves can take quick action when the owners are sleeping or going to the restroom.

On June 12 a popular Vietnamese singer posted on her Facebook page that she had her portable luggage stolen during a flight from Brussels from Bangkok.

The thieves emptied the handbag that she had kept under her feet during the flight, the singer wrote.

Fortunately, since she had experienced theft during a flight before, the singer only had some money in the bag, and thus the financial damage was not big, she said.

“My cell phone, purse, and passport are safe, but the money is gone,” she wrote.

The singer also said her little sister and several other passengers on the same flight had belongings stolen.

On April 19, three passengers fell prey to thieves during their flight from Singapore to Cambodia.

Shortly after their Silk Air flight, coded MI 602, landed at Phnom Penh International Airport, three Singaporean passengers discovered that they had lost more than $3,000, according to The New Paper.

Two Chinese nationals were suspected, according to eyewitnesses, but a search conducted by Cambodian police later found nothing on them.

However, Xu Chang Kai, 47, of Chinese nationality, was later arrested and charged with the theft on May 1, The New Paper said.

Chinese thieves

Chinese nationals dominate the list of thieves and suspects on the recently reported airplane cases.

For instance, two Chinese men allegedly stole money and other assets from passengers on a Vietnam Airlines flight on October 29, 2012 by rummaging through their luggage.

The two men repeatedly walked up and down the aisle and searched the portable luggage of other passengers, according to one of the passengers on flight VN593 from Hong Kong to Hanoi.

The eyewitness said the Chinese men took advantage of the fact that most of the passengers had fallen asleep during the long five-hour flight, and “even opened some of the bags.”

A Japanese passenger in seat 32C said he lost thousands of US dollars, but Noi Bai police could not find the money on the Chinese men upon their arrival.

The Chinese nationals were asked to return to Hong Kong on October 30, police said.

Elsewhere, in Singapore, local police told AFP on May 29, 2012 that the in-flight thefts are believed to be conducted by a Chinese crime syndicate.

Eighteen reports about in-flight thefts were filed in 2012, AFP quoted Sam Tee, head of the airport police division, as saying.

Tee told AFP that the thieves usually work in groups of three to four individuals per flight.

“They strike during boarding, or in-flight when passengers are asleep or using the toilets.

“Their goal is to steal cash which has been kept by passengers inside their travel or laptop bags stowed in the overhead compartments of the aircraft.”

In April 2012, Singapore jailed Fu Xinping, a Chinese national, for four weeks for stealing $800 and HK$3,000 ($386) from a fellow Chinese national’s bag on a Hong Kong-bound Singapore Airlines flight, according to AFP.