quake
A 6.8 magnitude earthquake that also measured a strong 5 on the shindo (intensity) scale struck off Japan's northeastern coast on Saturday but no tsunami warning was issued, Japanese and U.S. authorities said, with no immediate reports of damage.

The United States Geological Survey (USGS) said the midmorning quake hit at a depth of 47 kilometers (29 miles) in the Pacific, off Ishinomaki, Miyagi prefecture, near the epicenter of the huge March 2011 quake that triggered a towering tsunami, killing more than 18,000 people.

The USGS and Meteorological Agency said there was no tsunami risk following the jolt, which produced strong shaking along parts of the eastern coast and was also felt in Tokyo.

Officials in Aomori, Fukushima and Iwate said no casualties had been reported and public broadcaster NHK said there were no immediate reports of damage.

But a Meteorological Agency official warned strong aftershocks may hit the region in about a week, adding that expected bad weather may trigger landslides following the latest ground shaking.

Two people were slightly injured after windows were broken at a station in Onagawa, Miyagi, NHK said.

"We are aware of the news but still collecting information," said Kazuto Takeda, an official with the prefecture's disaster management office.

NHK also said a woman in her 80s was treated in hospital after she fell at a supermarket in Fukushima.

Some sections of expressways and train services, including those on the Tohoku Shinkansen Line, were suspended following the temblor, which was also felt in Tokyo.

Tokyo Electric Power Co. Holdings is checking for any irregularities at its nuclear power plant in Fukushima, according to NHK. Tohoku Electric Power Co. found no abnormalities at its Onagawa, Higashidori nuclear plants, according to a spokesperson.

Saturday marked the first day of a five-day holiday and a number of people were seen evacuating from JR Sendai Station, with university student Asuka Koike, who was on her way to her hometown in Fukushima Prefecture, saying, "I don't know what to do. I'm afraid as there have been many earthquakes recently."

Japan sits on the Pacific "Ring of Fire," an arc of intense seismic activity that stretches through Southeast Asia and across the Pacific basin.

The country is regularly hit by quakes, and has strict construction regulations intended to ensure buildings can withstand strong tremors.