TOKYO - A 7.2-magnitude earthquake rocked a rural, mountainous area of northern Japan on Saturday, killing at least two people, triggering landslides, stopping train service and knocking down a bridge. With roads closed, military aircraft and helicopters were mobilized to assess the damage.

Kyodo News agency said at least 100 people were injured. Officials confirmed 69 injuries and seven people missing. Another 100 people were trapped at a hot springs, according to the government's Disaster Agency, but details of their situation remained unclear.

Two nuclear power plants in the area were being inspected, but there were no immediate reports of damage, said Chief Cabinet Secretary Nobutaka Machimura. Ten nuclear reactors at the two power plants in Onagawa and Fukushima were running normally, operators Tohoku Electric Power Co. and Tokyo Electric Power Co. said.

However, electricity had been cut to about 29,000 households in the quake zone.

One of the deaths was a man who ran out of a building in fear and was hit by a passing truck, and the other confirmed death was a man who was buried in a landslide while he was fishing, Machimura said.

There was no danger of tsunami, but several aftershocks, including one with a magnitude of 5.6, struck the area in the hours after the initial temblor. Meteorological Agency official Takashi Yokota said at least 40 aftershocks occurred in the area and could trigger further damage to buildings or cause landslides.

The 8:43 a.m. (2343 GMT Friday) quake was centered in the northern prefecture (state) of Iwate about 250 miles (400 kilometers) northeast of Tokyo, and was located about 5 miles (8 kilometers) underground _ revised from an initially estimated depth of 6.2 miles (10 kilometers). It was felt as far away as the capital.

"It shook so violently that I couldn't stand still. I had to lean on the wall," said Masanori Oikawa, an Oshu city official who was at home near the epicenter when the quake struck. "When I rushed to the office, cabinets had been thrown onto the floor and things on the desks were scattered all over the place."

The government said 69 people were confirmed injured, but reports gathered from local authorities indicated at least 100 people had been hurt.

"Damage appears to be growing, but we can't even go out there to assess the situation with roads closed off because of landslides," said Norio Sato, a city official in one of the hardest-hit cities, Kurihara.

In that city, a landslide swallowed 15 construction workers, leaving three of them still missing, while the remaining managed to climb out on their own. Four people at Komanoyu hot springs were also missing after a separate landslide hit the resort hotel, according to another city official, Katsuyuki Sato.

The Defense Ministry dispatched a dozen helicopters and patrol aircraft to the region to conduct flyovers and assess the extent of damage. The government also sent a CH-47 helicopter carrying Disaster Minister Shinya Izumi to the region.

Local governors had asked for more troops to help in rescue and assessment operations.

Footage shot from media helicopters showed landslides on rural roads running along knots of mountains separated by long stretches of rice fields.

Footage aired on national broadcaster NHK also showed a bridge that collapsed. NHK said four people were seriously injured while riding on a bus over a bridge when the quake hit, but it was unclear whether it was the same one.

"We must assess the situation as quickly possible and do utmost in our relief activities," said Machimura.

Footage from the closest large city, Sendai, showed the force of the quake shook surveillance cameras for 30 seconds. NHK interviewed an official from Miyagi prefecture, where Sendai is located, who said he saw tiles coming off the roofs of some homes.

"It was scary. It was difficult to stand up," said Sachiko Sugihara, a convenience store worker in Oshu in a separate interview with NHK. "The TV fell over and the refrigerator shook."

Windows broke at a nursery school in the area and NHK said some teachers and children were injured, though it was unclear how seriously.

Sendai appeared largely unscathed.

"So far we have not received any reports of damage or injuries. Everything is normal," Hideki Hara, a police official in Sendai, told the AP. "Phone lines, water and electricity are all working right now."

Japan is one of the most earthquake-prone areas in the world. The most recent major quake in Japan killed more than 6,400 people in the city of Kobe in January 1995.