TOKYO (Reuters) -- A moderately strong earthquake measuring 5.0 on the open-ended Richter scale rocked Tokyo and surrounding areas on Wednesday, but there were no immediate reports of damage or injuries and no “tsunami” warning was issued.

Flights at Narita Airport outside Tokyo were not affected, but Haneda Airport, which handles mostly domestic flights, closed its three runways for checks.

As buildings in the capital swayed, services on one local train line were halted and others reduced speed as a precaution.

Public broadcaster NHK said Shinkansen bullet train services between Tokyo and Odawara in nearby Kanagawa prefecture were halted after the earthquake but resumed after a brief stoppage.

The epicenter of the temblor, which struck at 04:30 P.M. (0730 GMT), was 80km (50 miles) beneath the earth's surface east of Tokyo. Japan sits atop the junction of at least three tectonic plates, immense slabs of the earth's crust whose gradual movements are thought to cause earthquakes, making it one of the world's most earthquake-prone regions.

A powerful earthquake registering 8.0 on the Richter scale rocked Japan's northern island of Hokkaido late last month, injuring nearly 600 people and causing a fire to break out at an oil refinery.

Japanese still have vivid memories of an earthquake in the western city of Kobe that killed more than 6,400 people eight years ago. That quake measured 7.2 on the Richter scale.

The Great Kanto earthquake of September 1, 1923, measured 7.9 on the Richter scale and killed more than 14,000 people in Tokyo and the neighboring port city of Yokohama.