Smartphone giant Samsung has reportedly stopped production of its Note 7 phone amid claims that replacement devices still have critical battery issues.
Reuters and South Korea's Yonhap news agency cited unnamed officials claiming the company had temporarily halted its Galaxy Note 7 production lines.
Samsung told the BBC it was "adjusting the production schedule to ensure quality and safety matters".
The move came as two US networks stopped replacing or selling the phone.
Samsung said on Monday it would also stagger shipments of the Note 7 to conduct in-depth inspections.
The South Korean firm issued a recall of the smartphone in September and assured customers last month that the fixed devices were safe.
But there have now been several reports of replacement phones starting to emit smoke.
'No longer exchanging'
It comes after the AT&T and T-Mobile networks in the US said they would no longer replace the devices, while the latter said it would halt all sales of the phone.
"While Samsung investigates multiple reports of issues, T-Mobile is temporarily suspending all sales of the new Note 7 and exchanges for replacement Note 7 devices," T-Mobile said on its website.
Meanwhile, AT&T said: "We're no longer exchanging new Note 7s at this time, pending further investigation of these reported incidents." It advised customers to exchange them for other devices.
Samsung said in a statement last month that the issue of overheating was caused by a "rare" manufacturing error that resulted in the battery's "anode-to-cathode [negative and positive electrodes]" coming into contact.
But last week, a domestic flight in the US was evacuated after a replacement Note 7 started emitting smoke in the cabin. And a man in Kentucky reportedly woke up to a bedroom full of smoke from a replaced Note 7.
In an update on Monday, Samsung said it understood the concerns of carriers and consumers about the newly released replacement Note 7 devices.
"We continue to move quickly to investigate the reported case to determine the cause and will share findings as soon as possible," Samsung said.
"If we conclude a product safety issue exists, we will work with the CPSC (US Consumer Product Safety Commission) to take immediate steps to address the situation."
The South Korean tech giant's shares fell 1.5% in Asian trade.