Online video showed the rocket called Kairos blasting off from Wakayama Prefecture, central Japan, a mountainous area filled with trees, but exploding midair within seconds.

A huge plume of smoke engulfed the area, and flames shot up in some spots. The video then showed spurts of water shot toward that spot in an effort to put out the blaze.

Tokyo-based startup Space One, behind the rocket launch, did not immediately respond to a request for comment. The launch was already delayed several times, with the last postponement coming Saturday, after a ship was spotted in a risk area, according to Japanese media reports.

If it had succeeded, Space One would have been the first private company to put a rocket into orbit.

Tokyo-based Space One was set up in 2018, with investments from major Japanese companies, including Canon Electronics, IHI, Shimizu and major banks.

There was no immediate reports of injuries or other damage. Japan's main space exploration effort is led by the government's NASDA, which stands for The National Space Development Agency of Japan, this nation's equivalent of NASA of the US.