A tsunami advisory was issued for the Pacific coasts of northern Japan after a strong quake hit the region heavily damaged by the March earthquake and tsunami, the Japan Meteorological Agency said Sunday.
The agency issued the advisory for Iwate, Miyagi, and Fukushima prefectures, after a 7.1-magnitude earthquake struck off the main island of Honshu at 09:57 am (0057 GMT).
The US Geological Agency, which also estimated the magnitude at 7.1, said the offshore quake hit at a depth of 10 kilometres (6.2 miles) in the same general area as the 9.0-magnitude quake of March 11 which triggered a massive tsunami.
Tokyo Electric Power Co (TEPCO) said it had not received reports of any fresh problems at the crippled Fukushima Daiichi nuclear plant after the latest earthquake.
"We are still checking details, but cooling of reactors is continuing," a TEPCO spokeswoman said.
A small tsunami of up to 50 centimetres (20 inches) was expected along the affected region, the meteorological agency said.
Communities along the Pacific coast issued warnings and advisories for local residents to seek higher ground but no damage had been reported shortly after the quake.
Television footage of the affected coasts did not show any visible signs of a tsunami or major changes in the waters.