MILAN (AP) — An Italian environmental group is reporting the sighting of a dead mother sperm whale and its baby, which became tangled in a fishing net in the Tyrrhenian Sea off western Italy.

The Marevivo group said Thursday that the Italian Coast Guard had responded and surmised that the mother while died trying to free its baby. Part of the fishing net was found in the mother whale's mouth while the baby while was completely covered by it.

Marevivo President Rosalba Giugni said the deaths were a loss "for our natural heritage, but knowing that what happened is our fault makes it even more tragic."

The deaths come after an 8-meter (26-foot) sperm whale was found dead off Sardinia in March with 22 kilograms (48 1.2 pounds) of plastic in its belly.