A whale beached itself and died over the weekend in Luquillo, a city on Puerto Rico's north coast, but the cause of death has not been determined, police said.

A necropsy will be done on the sperm whale to determine the cause of death, Manatee Conservation Center biologist Antonio Mignucci said.

The marine mammal weighed nearly 7,000 kilos (7.7 tons), which was less than the normal weight for its species, Mignucci said.

The sperm whale, which was about nine meters (nearly 30 feet) long, was bleeding and may have cut itself on the reefs offshore, the Department of Natural and Environmental Resources, or DRNA, said.

DRNA personnel found what appeared to be a placenta on the beach, so the whale may have aborted a calf, environmental officials said. EFE