Extortionists demanding 50 diamonds put cyanide in a jar of pickles and a bottle of teriyaki sauce on shelves in separate supermarkets and have threatened to "poison food in every Safeway store in the area," police said.

Notes signed "The Poison Gang" were found taped to the pickle jar in one Safeway store Saturday and to a bottle of teriyaki sauce in another Safeway store Sunday.

Deputy Coroner Jay Johnson said "enough cyanide to kill a family" was found in the pickles at the La Jolla area store.

Dr. Georgia Reaser, spokeswoman for the County Department of Health, said the poison also was found in the teriyaki sauce at the Pacific Beach store.

The incident began Saturday when a man telephoned the La Jolla store, about four miles from the store in Pacific Beach, and said a poisoned jar of pickles with a note attached could be found in the cooler. It said "five other food items loaded with cyanide . . . are now on the shelves of this store. If you comply with our demands, we will give you a list and the exact location of these food items. Otherwise, we will poison the food in every Safeway store in the area."

It demanded fifty loose diamonds of one carat or larger.

Police would say only that "negotiations" were under way with the extortionists.