A JAPAN Coast Guard elite rescue unit has picked up a dog that was adrift at sea on a house roof off the nation's tsunami-battered northeast coast, an official said today.

A helicopter crew on Friday spotted the floppy-eared dark brown animal adrift 2km from Kesennuma, a port town severely hit in the March 11 disaster, according to the coastguard official.

A member of a highly trained rescue unit nicknamed the "sea monkeys" by the Japanese public was lowered from the helicopter to catch the dog, but the engine roar scared it and it jumped to another piece of flotsam, he said.

"These rescuers are very specialised," he said. "They found the dog again from a boat and finally managed to rescue it."

The mid-sized dog, whose sex was not released, wore a collar and seemed to have been a house pet, the official said.

"But it has nothing else to indicate who the owner is. He is very friendly and looks fine. He eats biscuits and sausages," he said.

It was not known whether the animal had been adrift for the entire three weeks since the disaster struck.

The Japan Coast Guard is still searching for thousands of people missing after the magnitude 9.0 earthquake and tsunami struck, and deployed 54 ships and 19 helicopters on Friday alone.

A massive US-Japanese military search for bodies - with 25,000 personnel on aircraft, ships and on the ground - recovered just 32 bodies on Friday, the first day of the three-day operation.

Originally published as Japan rescuers find dog alive at sea