By Isabel Reynolds
TOKYO (Reuters) - A strong earthquake jolted northern Japanearly on Thursday, injuring dozens of people, trapping hundredsin halted trains and cutting off electric power to thousands ofhomes.
The Japan Meteorological Agency said there was no threat ofa tsunami from the quake, which struck at 12:26 am JST (4:26p.m. British time Wednesday) and had a preliminary magnitude of6.8 and could be felt as far away as Tokyo.
Chief Cabinet Secretary Nobutaka Machimura told reportersthat at least 26 people had been injured and 6,000 homes werewithout electricity. A National Police Agency official said the26 had suffered minor injuries such as cuts from broken glass.
"Once it's light, we'll have a better grasp of thesituation and helicopters will be able see things likelandslides," Machimura said after the government set up anemergency task force at the prime minister's officialresidence.
National broadcaster NHK put the injured toll at 56.
The focus of the quake was 120 km (75 miles) below thesurface of the earth in Iwate prefecture, a mountainous,sparsely populated region, the agency said.
"I woke up immediately. It felt like it was shaking for along time. Books and other things that were piled up fell onthe floor. All the doors were open and things were shattered,"Sho Koseki, a city official in Hachinohe, about 550 kmnortheast of Tokyo, told Reuters by telephone.
Koseki said that military troops had arrived in the area,and the Defence Agency said that military planes were flyingover the area to try to assess the extent of the damage.
STUCK IN TRAINS
East Japan Railway said more than 600 people were stuck onfive trains that were halted due to the quake.
There was a fire in one building in Hachinohe, a city witha population of about 240,000, and national broadcaster NHKshowed fire engines driving through the streets towards thescene of the blaze, but the fire was soon extinguished andthere were no reports of injuries.
Some parts of highways were closed to traffic in theregion, a mountainous and sparsely populated part of Japan, butthey were later reopened, NHK reported.
TV footage showed offices with papers strewn around on thefloor and some with parts of ceilings fallen down.
"People in the store were trying to protect dishes frombreaking," a young woman in the northern city of Sendai toldNHK.
"I thought the big one had finally come."
The Japan Meteorological Agency warned of landslides insome areas, where strong rain was expected in coming hours.
Tohoku Electric said its nuclear facilities in the areawere operating normally after the quake, except for one unitthat was already off-line for maintenance work.
Tokyo Electric said its nuclear plants further south hadnot been affected.
Nippon Oil said its 145,000 barrels per day Sendai refinerywas operating normally after quake.
But Tohoku Electric said it had manually shut down a250-megawatt oil-fired power plant in Aomori and Nippon Steelhalted steel output and shut down a 149-megawatt coal-firedpower plant at its Kamaishi works for inspection.
Earthquakes are common in Japan, one of the world's mostseismically active areas. The country accounts for about 20percent of the world's earthquakes of magnitude 6 or greater.
Thursday's quake follows a string of earthquakes in thesame region, the first of which in mid-June killed at least 10people and left as many again missing.
In October 2004, an earthquake with a magnitude of 6.8struck the Niigata region in northern Japan, killing 65 peopleand injuring more than 3,000.
That was the deadliest quake since a magnitude 7.3 tremorhit the city of Kobe in 1995, killing more than 6,400.
(Additional Reporting by Chris Gallagher, Yoko Kubota,Chisa Fujioka and Osamu Tsukimori; Writing by Linda Sieg;Editing by Hugh Lawson)
