TOKYO (Reuters) - A strong earthquake with a preliminary magnitude of 7.0 jolted northern Japan on Saturday, killing two people, injuring scores, and sending landslides sweeping across roads.

The quake, at 8:43 a.m. (7:43 a.m. ET), was centered in Iwate, a mountainous rural area around 300 km (190 miles) north of Tokyo, where the tremor was also felt.

One of those killed was a person caught in a landslide, Chief Cabinet Secretary Nobutaka Machimura told reporters. A second was killed as he ran out of his house and was run over by a car.

"I saw some shattered windows and broken roof tiles," a city hall worker in Miyagi prefecture told public broadcaster NHK. "There were no collapsed buildings."

Kyodo news agency said more than 80 people were hurt.

Four people were badly injured near the airport in the northeast coastal city of Sendai as a bus they were traveling in was jolted by the earthquake, TV reported. Machimura said the government had set up an emergency response centre.

THOUSANDS STRANDED

Two thousand people were stranded when bullet trains in the region were halted, a JR East spokesman said, adding it could take nine hours to complete safety checks and resume services.

Nuclear power plant operations were unaffected, although aftershocks continued and a government official said 22,000 people had lost electricity supplies.

The focus of the magnitude 7.0 tremor was 10 km (6 miles) underground in Iwate and Miyagi prefectures, the Japan Meteorological Agency said on its website. (http://www.jma.go.jp/en/quake/14090100384.html) No tsunami warning was issued after the quake.

Children and teachers at a daycare centre were injured, and some highways were closed, Japanese television reported, with aerial pictures showing landslides that had swept through a house and swamped some roads.

In worst hit areas, the earthquake was measured at an upper 6 on a Japanese intensity scale, which measures ground motion. It may be impossible to keep standing in a quake with that reading, the meteorological agency says.

"There was a strong vertical tremor, nothing after that," a municipal worker told NHK.

NUCLEAR PLANTS OK

A spokesman for Tokyo Electric Power Co Inc, Japan's biggest utility, said two of the company's nuclear power plants in Fukushima prefecture, just south of Miyagi prefecture, were running as usual and there were no disruptions from the quake.

An official at Tohoku Electric Power Co Inc said its nuclear plants at Onagawa and Higashidori were also operating as usual.

Top Japanese refiner Nippon Oil Corp's 145,000 barrel-per-day Sendai refinery appeared not to have been damaged after the quake, a company official said. The refinery is currently shut for scheduled maintenance.

Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater.

In October 2004, an earthquake with a magnitude of 6.8 struck the Niigata region in northern Japan, killing 65 people and injuring more than 3,000.

That was the deadliest quake since a magnitude 7.3 tremor hit the city of Kobe in 1995, killing more than 6,400.

(Additional reporting by Isabel Reynolds, Yoko Kubota, Linda Sieg, Yuzo Saeki, Chikafumi Hodo, Osamu Tsukimori; Writing by Hugh Lawson; Editing by Rodney Joyce and Jerry Norton)

www.reuters.com/article/idUST1820520080614