Rescuers and volunteers were racing to save about 100 pilot whales stranded on Sri Lanka’s western coast in the island nation’s biggest mass beaching.

The short-finned pilot whales began beaching at Panadura, shortly before dusk on Monday and within an hour, their numbers swelled to approximately 100, local police chief Sanjaya Irasinghe said.

“With the help of locals, we are trying to push them back [into the ocean],” Irasinghe said. “But they keep getting washed ashore. We are getting help from the navy to rescue these whales.”

As news of the Sri Lankan stranding spread, officials from the coastguard and navy arrived to help with the rescue, which went on late into the night.

Sri Lanka’s Marine Environment Protection Authority (MEPA), which was sending its officials to help with the rescue operation, said it was the largest single pod of whales stranded in the country.

“It is very unusual for such a large number to reach our shores,” MEPA chief Dharshani Lahandapura told AFP, adding that the cause of the stranding was not known.

“We think this is similar to the mass stranding in Tasmania in September.”

Sri Lankan Marine Biologist Asha de Vos posting on her Instagram feed stated that all except one female pilot whale had survived the stranding.

She also appreciated the efforts of the rescuers stating that ‘These people cared less about their own safety in the crashing surf than the safety of these animals, in a very difficult time in our planet’s history’.

The beaching of 470 pilot whales in a remote harbor in Australia’s southern island state of Tasmania was the country’s largest.

About 110 of the creatures were saved in a days-long rescue effort.

Pilot whales, which can grow up to six meters (20 feet) long and weigh a tonne, are highly social.

The causes of mass strandings remain unknown despite scientists studying the phenomenon for decades.

-With inputs from AFP/agencies