Locals on a remote island in eastern Indonesia on Tuesday cut up several dead pilot whales for food after a mass stranding that killed at least 41 of the mammals, an official said.

A total of 44 pilot whales beached themselves late Monday on the island of Savu in East Nusa Tenggara province, where there is a culture of whale hunting for consumption.

"Locals have hacked into around 11 whales so far and will probably use the flesh for meat," Savu fishery office chief Dominggus Widu Hau told AFP.

"When local fishermen found them before midnight, they were all still alive. But it was already late and there were not enough people to help push them back in."

More than a dozen fishermen, navy and police officers were still struggling Tuesday afternoon to keep the three surviving whales alive.

"We managed to push them back into the water, but they returned to the beach," Hau said.

Jakarta Animal Aid Network identified the mammals, which lay stranded around 150 metres (492 feet) from the coastline, as pilot whales. Those beached were between two and five metres long, Hau said.

Pilot whales commonly become stranded en masse since they stick together in large groups, especially if one is sick, according to marine biologists.