A series of small tsunamis hit northern Japan Wednesday following a powerful earthquake that struck sparsely populated islands to the north.

The first tsunami — a 16-inch wave — hit the port of Nemuro on Hokkaido at 7:29 a.m. ET, according to Japan's Meteorological Agency.

The agency said a second wave of half that height was recorded about 15 minutes later in the nearby port city of Kushiro to the southwest. At least three more small waves followed.

Japan issued a tsunami warning and told Pacific coast residents to flee to higher ground after a quake with a preliminary magnitude of 8.1 struck about 245 miles east of the island known as Etorofu, about 110 miles northeast of Hokkaido, at 6:15 a.m. ET.

The warning said a tsunami about 2 meters (6 1/2 feet) tall or higher was expected to hit the Pacific coast of Hokkaido, Japan's northernmost island.

Officials lifted the tsunami alert several hours after the quake, but urged continued caution.

Live footage from northern Japan after the first waves hit showed calm seas. Residents said they barely felt the quake and there were no immediate reports of damage or injuries.

A tsunami advisory was issued for Hawaii, where the Pacific Tsunami Warning Center said there was no threat of a destructive wave.

Cindy Preller, an official with the Alaska Tsunami Warning Center, said no tsunami was expected to hit the West Coast of North or South America. She said there was a slight chance one could hit the western Aleutian Islands.

Etorofu is one of four islands claimed by both Japan and Russia. It is known in Russia as Iturup. The chain of islands is known in Russia as the Kurils and in Japan as the Northern Territories.

The islands were occupied by the Soviet Union in the closing days of World War II. They are surrounded by rich fishing waters and are believed to have promising offshore oil and natural gas reserves. They also have gold and silver deposits. But the population has plummeted to just 9,900, according to official statistics.

A Russian official said a powerful earthquake had struck the Kuril Islands area and there was no immediate word of damage or casualties.

The U.S. Geological Survey reported on its Web site that a 7.8-magnitude quake had been detected 275 miles east-northeast of the Kurils at a depth of 17.2 miles. Temblors of magnitude 7 are generally classified as major earthquakes, capable of widespread, heavy damage.

The Pacific Tsunami Warning Center said a tsunami warning had also been issued for Russia.

A magnitude 9.1-magnitude earthquake off the coast of Indonesia on Dec. 26, 2004 caused a tsunami that killed at least 213,000 people in 11 countries. Those waves reached as high as 33 feet.

Tsunami waves, which are generated by earthquakes, are often barely noticeable in the ocean but can rise to great heights once they arrive at shore.

Japan is one of the world's most earthquake-prone countries because it sits atop four tectonic plates.

The Associated Press contributed to this report.