Anniversary: Japan mourns victims in 5th anniversary

Japan has observed the fifth anniversary of a devastating earthquake and resulting tsunami in the north-east, which caused the country's worst nuclear accident.

Later in the day, Emperor Akihito was to attend a government-sponsored memorial ceremony in Tokyo along with Prime Minister Shinzo Abe and disaster survivors.

The magnitude-9 quake and tsunami left 15,894 people dead and 2,561 missing, most in coastal areas in the Iwate, Miyagi and Fukushima prefectures, the National Police Agency said Thursday.

"I did not expect such a huge tsunami to hit this town," said Hisayo Aizawa, a resident of Ishinomaki, one of the hardest areas by the disaster.

"My neighbour urged me to evacuate to higher ground with her."

The waves killed her husband and swept away her rice store and house in the coast area on March 11, 2011. Aizawa and her family have lived in temporary housing in the city for four and a half years.

She is among the 16,022 residents who still live in cramped temporary housing in Ishinomaki, which accounts for about 11 per cent of its population.

As of mid-February, the number of total evacuees stood at 174,471, compared with 470,000 at its peak, the government said.

Evacuees in Ishinomaki said they are concerned about a further delay in the reconstruction as the country's attention turns to preparations for the 2020 Tokyo Olympics.

Critics say the reconstruction of the disaster-stricken areas is also held up by red tape.

Core meltdowns occurred at three of the six reactors of the Fukushima Daiichi Nuclear Power Station, run by Tokyo Electric Power, after it was struck by the quake and tsunami.

About 100,000 people have been unable to return to their homes near the complex due to radiation contamination.

Sachiko Mashio and her family finally settled in a house in Saitama, north of Tokyo, last year after several relocations. Her husband has suffered ill health.

"I never expected to move more than 10 times in my life," said Mashio, who used to run a restaurant in Namie town, 20 kilometres north of the plant, before the accident.

Mashio has no expectation of going back to Namie even if the evacuation order is lifted, she said.

"My house was in wild disorder as it was apparently burgled a number of times."

It is expected to take the operator more than four decades to complete the decommissioning process.