In Miyazaki prefecture's Nichinan city, the ash had cast a dark pall across the city forcing residents and children heading to school to wear protective masks. The ash then fell on roads, which cars then churned up into an ash fog.

Elementary School Student said, "I couldn't see the crossing signs so we didn't know where to cross."

Another resident said he even found his car's rear window broken by projectile rocks from the mountain.

Car Owner said, "It came like a sudden downpour of rain. It collapsed the window of my car just as I opened the door to take refuge."

No-one so far has been seriously hurt but many railway lines and highways have been closed in the vicinity of the volcano.

At least four domestic flights from Tokyo to Miyazaki have been cancelled due to the volcanic ash.

Japanese media say local volcanologists expect more activity in the next few days even if no major eruptions are expected any time soon.