The science ministry has raised the nation's crisis alert for space radio disaster after occurrence of the Earth's magnetic field disturbance due to solar activity.

The ministry said the alert level was raised by a notch from the lowest "attention" to "caution" on the four-tier scale at 9:30 a.m. Saturday.

The ministry and the Korean Space Weather Center have begun operating an emergency system under a related manual, which includes monitoring of possible damage in aviation, navigation, electricity and the ocean.

With no damage being reported as of 11 a.m., the ministry said a stronger and continuous radio environment change could cause aviation radiation exposure, GPS reception hindrance, and satellite orbit breakaway.

It then pledged to maintain a system of around-the-clock monitoring and damage prevention.