Hundreds of police and coastguard officers were Tuesday searching for the remains of around 2,800 people still missing 18 months to the day after a massive earthquake and tsunami hit Japan.

About 800 officers scouted beaches and rocks or probed waters with boats and underwater robots along the rugged Pacific coast northeast of Tokyo, according to media reports.

The disaster, on March 11 last year, left 18,684 people dead or missing and sparked reactor meltdowns at the Fukushima nuclear power plant on the coast, figures from the National Police Agency showed.

Of those, 2,814 people remain unaccounted for.

In addition 1,632 people have died of disaster-related causes, such as fatigue and bad health from living in evacuation shelters in the three northeastern districts of Iwate, Miyagi and Fukushima, Kyodo news agency said.

Some 343,000 people are still living in about 136,000 temporary homes, such as makeshift houses and private properties rented by the government.

Nearly half -- 161,000 people -- remain unable to return to their homes in Fukushima amid fears of radiation from the stricken power plant, the district's administration said Tuesday.

In the city of Kesennuma, about 10 officers searched a fishing port where a set of skeletal remains was recovered last month, according to local media.

"We will strenuously continue the search in order to help return remains to families as soon as possible," Kesennuma police director Rinji Ono told public broadcaster NHK.