Eleven dead whales were discovered Sunday afternoon on a remote island in the Florida Keys, CBS News 12 reported.

The sea creatures that were discovered on Snipe Point, about six miles north of Sugarloaf Key, are likely from the pod of stranded whales "that had been the focus of an intense rescue effort" last week, Blair Mase, stranding coordinator for National Oceanic and Atmospheric Administration Fisheries, the main federal marine conservation agency, told reporters in a conference call.

NOAA said it's suspected that the whales came from a pod of 51 pilot whales that were stranded on the Gulf Coast of Florida's Everglades National Park.

"We think these are from the same group," Mase said. "We expected this would happen."

CBS News 12 reported that of the original group of 51 whales found stranded, 22 are now known to be dead, assuming the dead whales found Sunday came from that group. The first six beached on the Gulf coast of the park early last week, four were euthanized after being discovered nearby near death and another was later found dead.

Since the whales were discovered off the coast of West Everglades last week, they have been the focus of a rescue campaign that attracted "international attention, with boats and helicopters from various state, federal and local agencies," CBS News 12 reported.

No cause has been determined for the strandings, which could have place for a variety of reasons, both natural and man-made.

"Pilot whales are the most common for mass strandings in Florida," Mase said. "Pilot whales are a very cohesive species. They typically follow one another inshore."

Mase said officials will look into whether a virus spreading among dolphins and whales in the Atlantic could have been involved.

The dead whales were discovered by the Florida Fish and Wildlife Conservation Commission. A NOAA team was headed out to the site Sunday, and veterinarians will perform necropsies on them Monday.