It could not come at a better time as Apple is just about to announce the release of its iPhone 7 which is basically a dull refresh of its earlier models and had not been expected to sell well against the Galaxy Note range.

The tech giant said it would prepare replacement devices for those already sold. It was not immediately clear when new sales of the devices would begin. Samsung Electronics launched the Note 7 on August 19 in markets including the US. The Galaxy Note 7 smartphone is the latest iteration of Samsung's Note series. It features a giant screen and a stylus

South Korean high school teacher Park Soo-Jung told  Associated Press she bought the Galaxy Note 7 and activated it on August 19.However her phone later burst into flames, filling her bedroom with smoke smelling of chemicals.

An employee of a Samsung service center in Busan who visited Park's school to retrieve the scorched phone confirmed that her Galaxy Note 7 caught fire and said the sample was sent to the company's headquarters.

"If the exploded phone in flame was near my head, I would not have been able to write this post," she said in a popular online forum on Thursday, where she shared a photo of the scorched Note 7 and described dousing the burning phone with water.

There had been an earlier explosion but this was thought to be the result of a dodgy third party cable and while that still could be the case, it is clear that there is something wrong with the Note 7's battery.