2 sperm whales managed to swim back to deeper waters and 5 died by Saturday on the Italian southern shore.

9 whales measuring up to 12 metres in length were stranded Thursday on a beach in Puglia.

The reason was the caused from military exercises or surveys for underwater mineral deposits noise, which confuses whales and interfere with their communication. That said the marine biologist Giuseppe Notarbartolo di Sciara,

"When a sperm whale washes up on the beach it's usually already dead," he said. "When an entire pod ends up on the shore it's difficult to think that the cause is natural, otherwise it would happen more often."

This said Nicola Zizzo, one of the veterinarians caring for the animals, and commented that the officials were considering euthanizing the last two whales still trapped in high waves just off the beach.

The rough seas were making it difficult to understand even how many whales were still alive, with other experts telling media that only one was breathing.

The sperm whale is the largest of all toothed whales and is considered a vulnerable species.

While similar mass beachings are more common in the oceans, they are extremely rare in the Mediterranean, occurring once every 150-200 years.

Scientists had taken tissue samples to try to determine the cause of the beaching and authorities were working on the difficult job of burying the huge carcasses.

View a video of a burial, courtesy of the Register-Guard.

Photo credit: 

MARIO LAPORTA/AFP

Vincenzo Maizzi/AP Photo