Tsunami hits Japan after strong quake near Fukushima disaster site

A powerful earthquake rocked northern Japan early on Tuesday, briefly disrupting cooling functions at a nuclear plant and generating a small tsunami that hit the same Fukushima region devastated by a 2011 quake, tsunami and nuclear disaster.

The magnitude 7.4 earthquake, which was felt in Tokyo, sent thousands of residents fleeing for higher ground as dawn broke along the northeastern coast.

According to Reuters news agency, there were no reports of deaths or serious injuries several hours after the quake hit at 5:59am local time (21:59 CET Monday)

The quake was centred off the coast of Fukushima prefecture at a depth of about 10 kilometres, the Japan Meteorological Agency (JMA) said.

In a statement, the agency said the earthquake was thought to be an aftershock of the 9.0-magnitude event that devastated the same region in 2011. The region was also hit by a series of weaker quakes throughout Tuesday.

A wave of up to 1.4 metres in height was recorded at Sendai, about 70 km north of Fukushima, with smaller waves hitting ports elsewhere along the coast, public broadcaster NHK said.

The Pacific Tsunami Warning Center in Hawaii said the tsunami threat had now largely passed and the JMA later lifted its warnings.

The Tokyo Electric Power Company said it had restored a cooling system at the Fukushima Daini nuclear power plant that briefly stopped after the quake, national broadcaster NHK reported.

The car maker Nissan suspended work at its Fukushima factory, which was badly damaged by the 2011 disaster known as the Great East Japan Earthquake. A spokesman for the company told the Guardian all employees had been evacuated from the plant, which is in the city of Iwaki, and the factory was unlikely to return to operation on Tuesday.

Meanwhile, firefighting officials in Iwaki in Fukushima said a fire broke out at a petrochemical complex and was later extinguished, NHK said.