Two Samsung Galaxy Note 7 smartphones reportedly have caught fire in China.
If it confirmed, it would be the first such incidents in the world's largest smartphone market.
Samsung Electronics said it was investigating one of the reported cases.
The South Korean firm had earlier said Galaxy Note 7 smartphones sold in China were safe to use.
A user of Chinese social media posted messages on Sunday saying a friend's Note 7 caught fire over the weekend.
The user, contacted by phone, said the Note 7 was bought Sept. 1 through the JD.com e-commerce site.
The man, who asked not to be identified by name, said the phone started to heat up and vibrate late Saturday night, then exploded and emitted black smoke.
Samsung contacted the owner on Sunday and offered to take back the phone in exchange for a refund, but the owner refused, according to the friend.
He said he and the owner didn't want to be identified by name.
A second account on a separate social media account said an owner's phone exploded while the person was playing a game on it.
Samsung Electronics launched the Note 7 phone in China on Sept. 1 amid a growing number of reports of the phones catching fire overseas.
The following day, Samsung announced that it would stop sales of the Note 7 phones in 10 countries.
An executive said sales in China would continue because Note 7 phones sold there used a different battery than those linked to problems elsewhere.
Samsung is recalling 1,858 Note 7 phones in China, according to a notice dated Sept. 14 from the country's product quality agency.
Samsung said those phones were distributed before Sept. 1 to give consumers hands-on experience.
The recall in China applies to phones made between July 20 and Aug. 5, according to AP.