A Japanese city devastated by the 2011 tsunami has received anonymous gifts of gold worth more than $250,000 in a phenomenon dubbed a "goodwill gold rush" ahead of the second anniversary of the disaster.

The president of the company which operates the port in the northeastern city of Ishinomaki last week received a parcel containing two slabs of gold each weighing one kilogram (2.2 pounds).

"Since it was labelled as 'miscellaneous goods,' I casually opened the box," thinking it must be books or the like as it was heavy, said Kunio Sunow, president of the Ishinomaki Fish Market Co. Ltd.

"I was stunned because what's in there was 24k gold in two plates. One was wrapped in brown paper and the other in a page taken from a magazine -- both were sitting in bubble sheets," he told AFP by telephone on Saturday.

The parcel had been sent anonymously from Nagano city northwest of Tokyo with no message.

"Just looking at 24k gold can encourage people as it has a presence. It's great to know we haven't been forgotten," Sunow said, adding he had not yet decided how to use the gift.

Japanese media said a non-profit group in Ishinomaki that has been supporting its revival had also received two kilograms of gold bullion and at least one more group got more than one kilogram.

The gifts have mystified Japanese people, prompting the mass-circulation Asahi newspaper to call the phenomenon a "goodwill gold rush" in Ishinomaki.

The city, some 350 kilometres (220 miles) northeast of Tokyo, was devastated by the 9.0 earthquake and massive tsunami it generated on March 11, 2011.

The disaster killed nearly 19,000 people, including more than 3,000 in Ishinomaki, and sparked the world's worst nuclear accident in a generation.