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MEXICO CITY — Mexican authorities say dozens of dolphins have been found stranded on a rocky beach along the coast of Baja California Sur state.

The federal environmental protection agency says 54 of the marine mammals came onshore in the area of La Paz Bay. Workers attended to the dolphins and saved 33 of them, but 21 died.

Beached dolphins at La Paz, Baja California. PROFEPA

The agency said Tuesday in a statement that they were short-beaked common dolphins. Marine experts believe an attack by a group of bottlenose dolphins provoked the mass beaching.

Photos released by the agency show dozens of dolphins washed up on the rocks and lined up in the sand, overseen by white-coated personnel.