TOKYO (Reuters) - An earthquake with a preliminary magnitude of 5.5 hit eastern Japan on Saturday but no tsunami warning was issued, Japan's national broadcaster said.

There were no reports of immediate damage.

On March 11, 2011 Japan's north-east coast was struck by a magnitude-9 earthquake, the strongest quake recorded in the country, triggering a massive tsunami and resulting in the world's worst nuclear crisis in 25 years. The disaster left up to 20,000 dead or missing.