Lab says Fla. Keys tar balls are not from Gulf oil spill
The Coast Guard says tar balls that floated ashore in the Florida Keys aren't linked to the Gulf of Mexico oil spill.
A report released Wednesday says tests by a Coast Guard laboratory show the tar balls don't match the type of oil from the Deepwater Horizon spill.
The source of the tar balls isn't known.
Tar balls can occur naturally or come from other sources such as ships.
Twenty were found Monday and several others Tuesday.