EVERGLADES NATIONAL PARK, Fla. >> National wildlife officials say 11 whales believed to be part of a pod that was stranded in the Everglades are dead.

National Oceanic and Atmospheric Administration official Blair Mase says wildlife workers spotted the dead whales Sunday afternoon on Snipe Point, about six miles north of Sugarloaf Key.

That brings the overall death toll to 22.

The pod of 51 short-finned pilot whales was first spotted by a fishing guide Tuesday in the shallow waters off a remote section of the Everglades. The species is one of the most commonly involved in mass strandings.

Mase says that veterinary teams will try to determine whether any disease was a factor in the deaths.

Officials do not know the status of the remaining whales. The marine mammals were last seen alive Friday.