Aviation authorities are ramping up warnings about the Samsung Note 7 smartphone as problems with supposedly safe replacement units have prompted the Korean manufacturer to halt production.

The US Federal Aviation Administration and Australia’s Civil Aviation Safety Authority  have  renewed warnings in recent days urging passengers not to use the phone on aircraft.

“We're urging all passengers with this phone—including replacement devices—to follow the instructions of their airline,’’ CASA said on Tuesday.
“If there are no instructions, then passengers should switch-off the phone, refrain from use or charging and not pack it in their checked luggage.’’

Airlines around the world have been warning passengers about using the Note 7 after a slew of problems with the smartphone’s battery catching fire or overheating.

Samsung recalled 2.5 million units but was forced to halt production when purportedly safe replacement phones also overheated.

The BBC reported that owners were expected to be able to return the phones for a refund or an exchange for a different Samsung phone.

"We recently readjusted the production volume for thorough investigation and quality control, but putting consumer safety as top priority, we have reached a final decision to halt production of Galaxy Note 7s," Samsung said in a statement. "For the benefit of consumers' safety, we stopped sales and exchanges of the Galaxy Note 7 and have consequently decided to stop production."

Smartphones have become  a problem for airlines and many have started warning passengers not to move their seats and to call cabin crew if they lose their phone. This follows a number of instances where phones began smoking after they were crushed by the seat mechanism as passengers  attempted  to retrieve them.