Travelers in China have been caught off guard in recent days when they arrived at airports to be told they could not bring certain portable batteries aboard their flights.

       The country’s aviation regulator has implemented an emergency ban on some portable batteries aboard flights. The ban, which went into effect Saturday after just two days’ notice, came as the regulator warned of growing risks to the aviation industry from batteries, millions of which have been recently recalled.

       Airlines and governments around the world have tightened regulations on the use of portable batteries on flights this year. But while other airlines have largely issued guidelines on the in-flight use and storage of portable batteries, China’s order prohibits passengers from taking some batteries on board planes altogether.

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