Korea's space science institute on Thursday issued a warning following a massive solar flare or ejection of energy believed to be the strongest ever to be observed.

The solar flare, the third of its kind this year, was observed around 9 a.m. Wednesday (Seoul time) and was categorized as the highest X-Class, according to the Korea Astronomy and Space Science Institute.

A solar flare is the brightening of the sun's surface, which is a sign that large amounts of energy have been released by the star. The development causes a release of electrons, atoms and other particles into space.

The state-run institute said powerful protons were approaching the earth at a speed of 2,200 kilometers per second and will reach the earth later in the day.

"When the solar energy reaches the earth, it may cause a geomagnetic storm, which can affect high-frequency communications and global positioning systems," the institute said in a news release.

"By size, a solar flare that took place on Aug. 9, 2011 is still the largest of its kind yet to be seen, but the latest is the strongest in history in terms of the amount of energy released." (Yonhap)