The quake struck near Fukushima at about 06:00 local time (21:00 GMT Monday), triggering initial warnings of 3m (9.8ft) high waves. The waves which eventually hit the coast were much smaller. Thousands were asked to evacuate the area and minor injuries were reported.An earthquake and tsunami struck the area in 2011 killing 18,000 people. That quake, one of the most powerful ever recorded, also caused a meltdown at the Fukushima nuclear power plant, where a massive clean-up operation is still going on. Officials have said there is no sign of damage to the plant this time.