Tsunami warning issued as magnitude 6.8 earthquake strikes off Japan coast

A powerful earthquake has jolted northwestern Japan, with officials warning of a tsunami of up to 3.3 feet high along parts of the coast.

Japan's Meteorological Agency said the quake, which happened on Tuesday night local time, registered magnitude 6.8 and was located off the western coast of Yamagata about 30 miles southwest of the city of Sakata.

It said the quake's epicenter was fairly shallow, about 10km below the sea's surface. Shallow quakes tend to cause more damage on the Earth's surface.

The agency predicted a tsunami as high as 1m along the coast of the northwestern prefectures of Yamagata, Niigata and Ishikawa.

All seven reactors at the Kashiwazaki-Kariwa nuclear plant in Niigata were off line and no abnormalities were reported.

There were no immediate reports of damage or casualties from the quake, which hit 85 km (53 miles) from the island of Honshu.

Yesterday, an earthquake struck south-west China, killing at least 12 people and injuring another 135.

Rescue efforts are underway in the country’s Sichuan province after the 6.0 magnitude tremor hit late on Monday night.

More than 4,400 people have been evacuated after 73 houses collapsed in the quake, which was followed by several powerful aftershocks.

It comes after a magnitude 9.1 earthquake - the largest to ever hit Japan - triggered a tsunami with waves up to 40.5 metres high in 2011.

More than 22,000 people died and hundreds of thousands left without homes.

The earthquake caused a nuclear meltdown at the Fukushima plant and plunged the economy into recession.

Earlier this year, a powerful earthquake measuring magnitude 7.5 struck Papua New Guinea, triggering a tsunami alert for coastal areas up to 620 miles away.

The 7.5 magnitude quake struck 45km northeast of Kokopo, the provincial capital of the Papuan island of East New Britain, according to the US Geological Survey.

Agencies contributed to this report.