TOKYO (AP) — One of the strongest earthquakes ever recorded struck off Russia’s sparsely populated Far East early Wednesday, sending tsunami waves into Japan, Hawaii and the U.S. West Coast. Several people were injured, but none gravely, and no major damage has been reported so far.

Authorities warned the risk from the 8.8 magnitude quake could last for hours, and millions of people potentially in the path of the waves were initially told to move away from the shore or seek high ground.

But the danger already appeared to be lessening in some places, with Hawaii and parts of Japan downgrading their warnings. Authorities on Russia’s Kamchatka peninsula near the quake’s epicenter canceled their tsunami warning.

Residents fled inland as ports flooded on Kamchatka near the quake’s epicenter, while frothy, white waves washed up on the shore in northern Japan. Cars jammed streets and highways in Honolulu, with standstill traffic even in areas away from the sea.

People flocked to evacuation centers in affected areas of Japan, with memories fresh of the 2011 earthquake and tsunami that caused reactor meltdowns at a nuclear power plant. No abnormalities in operations at Japan’s nuclear plants were reported Wednesday.