SEOUL (AFP) – Multiple fires were raging in the northeast of North Korea recently, with a plume of smoke extending far out over the ocean, according to satellite photos seen Thursday.

Official media in the communist state has made no mention of the apparently massive wildfires.

The true-colour image captured by the National Aeronautics and Space Administration?s Aqua satellite on October 15 showed the northeast skies covered by great plumes of smoke extending over the Sea of Japan (East Sea).

"The smoke plumes blow uniformly eastward, some of the individual plumes coalescing into a single large plume over the sea," the caption read.

"Red outlines indicate hotspots associated with active fires, although not all the fires have visible hotspots," it said.

South Korean intelligence officials were unsure about the nature of the fires.

"We are still trying to analyse it," an official told Yonhap news agency. "One possibility is forest fires. But we are not certain about what it is, what caused it and what it looks like at the moment."