TOKYO (Reuters) - A magnitude 6.1 earthquake struck off Japan's north-eastern coast on Wednesday (April 20), the US Geological Survey said. There was no immediate tsunami warning, or reports of damage or casualties.

A series of strong quakes struck the south of Japan late last week killed at least 58 people. On Wednesday, survivors struggled with shortages of food and water.

The USGS said Wednesday's quake was centred 104km east south-east of Sendai, Honshu, near where a devastating quake and tsunami struck in March 2011. It was 51km deep.