Japan is marking the fifth anniversary of the earthquake and tsunami that left more than 18,000 dead or missing, the BBC reports.

PM Shinzo Abe and Emperor Akihito are attending a memorial in Tokyo, and joined a moment of silence nationwide at the exact moment the quake hit.

The magnitude-9.0 quake struck offshore, creating a vast water surge that devastated the north-east coast.

It also triggered the world’s worst nuclear disaster since Chernobyl, at the Fukushima Daiichi nuclear plant.

Water inundated the plant, taking cooling systems offline which set off a series of meltdowns.

The subsequent disaster spewed radiation over a wide area and forced the evacuation of more than 160,000 local people.

Five years on, most have not been able to return to their homes, despite extensive decontamination work.