SENDAI, Japan — A powerful magnitude 7.2 earthquake struck northeastern Japan on Tuesday and injured at least 60 people, triggering a small tsunami, sending debris crashing into a crowded swimming pool and shaking skyscrapers as far away as Tokyo.

More than 200 people, many of them children on summer vacation, were in an indoor pool in coastal Sendai city when the quake showered tiles and metal onto them, injuring 17, officials said.

Tumbling rocks and roof tiles hurt others elsewhere. TV news footage showed a collapsed house outside Tokyo and landslides in the quake-hit area, 300 kilometers (185 miles) north of the capital. An area police spokesman said an 80-year-old woman was trapped and later rescued.

"The shaking felt like it lasted forever. It was scary thinking when it was going to end and what was going to happen," said Sendai city official Yoji Kimura.

National broadcaster NHK said about 60 people were reported injured. Officials were still tallying figures, but police in Miyagi prefecture, which bore the worst of the quake, could only confirm 26 injuries. Neighboring Fukushima prefecture reported four.

"The horizontal shaking was very strong, so much so that I almost couldn't remain standing," said Masami Oshima, an official with Miyagi prefecture, of which Sendai is the capital.

The quake knocked out power to about 17,000 households, while high-speed train services in the north were suspended and flights temporarily grounded at Tokyo's Haneda airport. Nippon Oil shut a Sendai refinery.

"I thought my tires had punctured ... the jolt was long and slow," Shinji Abe, a taxi driver in Shiogama, outside Sendai, told Kyodo News agency. "People were running out of buildings."

The quake struck at around 11:46 a.m. (02:46 GMT) and was centered 20 kilometers (12.4 miles) below the ocean floor about 80 kilometers (50 miles) off the coast of Miyagi, the Meteorological Agency said. Two 10-centimeter (4-inch) tsunami waves hit the nearby coast shortly after noon, but officials expected little damage from the waves.

The quake was followed by at least four aftershocks, and agency official Yasuo Sekita warned area residents of possible aftershocks of similar strength.

"Please use caution the next few days at least, and beware of danger especially in areas where soil is loosened by rainfalls," he said.

The area is one of Japan's most earthquake-prone regions. Several powerful quakes have struck nearby in the past few decades, and the Education and Science Ministry earlier this year estimated it had a 99 percent chance of suffering a magnitude 7.5 quake in the next 30 years.

In 1995, a magnitude 7.3 quake in the western port city of Kobe killed 6,400 people. The depth and offshore location of Tuesday's quake helped limit the damage that might have occurred had it been centered under a city.

Authorities in Miyagi were still assessing damage.

The quake did not effect a nuclear power plant in neighboring Fukushima prefecture, the National Police Agency said.

Another plant in Onagawa in Miyagi shut down automatically and was being checked for damage, news reports said.

A falling stone lantern broke a 72-year-old man's leg, and two women were hurt when hot oil spilled on them in a supermarket, said Fukushima police spokesman Ichiro Oizumi.

Falling rocks injured a 7-year-old child in the town of Zao, said local official Mitsuharu Shishido.

Japan sits at the juncture of four tectonic plates, or moving slabs of the earth's outer crust, and is one of the world's most quake-prone countries. A magnitude 6.0 quake shook the Tokyo area on July 23, injuring more than two dozen people and suspending flights and trains for hours.

Earlier Tuesday, a 4.9-magnitude earthquake shook Japan's northern island of Hokkaido but did not trigger a tsunami.

Source: Associated Press