Japanese animal rescue volunteers have saved a porpoise from a rice field after it washed two kilometres inland by the March 11 tsunami.

Ryo Taira and his group were in the devastated area around Sendai rescuing cats and dogs when they received a phone call that took them a while to comprehend, the Asahi daily reported.

"There's a dolphin in the rice fields!" said the caller, Masayuki Sato, 55, confusing the baby porpoise with the similar-looking sea mammal.

The volunteers rushed to the site at nearby Ishinomaki, where they saw the animal - a finless porpoise or Neophocaena phocaenoides - wriggling in a flooded rice field.

They made a stretcher from car parts and a futon mattress they found in the tsunami wreckage and tried to catch the porpoise with a net.

When the animal eluded them, Mr Taira waded into the field in his rubber boots and picked it up in his arms, the report said.

With local aquariums damaged by the disaster, the volunteers decided to cover the animal in wet towels, put it in their car and return it to the sea.

"Immediately after I spotted it, I realised I could not ignore it. I had to do something. This was also a victim of the tsunami," Mr Sato later told the Asahi.

He said he remembered seeing the animal rescuers' phone number on a poster in a quake and tsunami evacuation centre.

Mr Taira told the newspaper of his thoughts as he watched the animal swim off into the Pacific Ocean.

"I don't know if it will survive, but it's much better than dying in a rice field, right? It's good," he said.

- AFP