SAPPORO -- Two powerful earthquakes, one with a preliminary magnitude of 8, struck Hokkaido early Friday, sparking a refinery fire and generating several tsunami.

At least 420 people were injured as of late Friday afternoon, Kyodo News said, while government officials reported there were 23 people who sustained injuries such as broken bones.

In a quake-related accident, a man was struck and killed by a car while cleaning up debris.