TOKYO (AP) – A strong earthquake rocked northeastern Japan late Wednesday, shaking buildings in Tokyo and nearby areas and briefly shutting down train lines. Two people were reportedly injured.

The earthquake, with a preliminary magnitude of 6.5, was centered 30 miles below the sea off the coast of Ibaraki prefecture, about 70 miles northeast of Tokyo, the U.S. Geological Survey said. There was no danger of a tsunami, officials said.

The quake shook 20 of the country’s 47 prefectures, said Takeshi Hachimine, a spokesman for Japan’s Meteorogical Agency. He said the region should brace for aftershocks measuring at least magnitude 5.0 over the next few days.

A woman in Ibaraki cut her nose after falling out of bed, while another slightly injured her hip near Tokyo, according to the Kyodo News agency. Police spokesman Meihan Toyoshima said no serious injuries had been reported.

A nuclear power plant in Tokaimura near the quake zone shut down automatically, but there appeared to be no damage, Toyoshima said. A Tokyo Electric Power Co. spokesman said electricity to about 600 homes in Ibaraki was cut off, but restored in less than a minute.

Officials at Tokyo’s Narita international airport said its runways were shut down after the quake but reopened in about 10 minutes.

High-speed train services north of Tokyo were suspended but quickly resumed.

, according to the company’s information hot line.

It was the second jolt in the area in recent days. A 5.1 quake outside Tokyo on Sunday shook the capital region and injured two people.

Japan, one of the world’s most earthquake-prone countries, sits atop four tectonic plates. The last major earthquake to hit Tokyo killed some 142,000 people in 1923.

AP-ES-10-19-05 1216EDT