FOUNTAIN HILLS, Ariz. -- Authorities continued searching a desert area east of Phoenix on Tuesday after hikers discovered ammunition and what appeared to be live hand grenades.
Maricopa County sheriff's officials said they found a second note claiming ``high explosives'' were hidden near the area of state Route 87 about 30 miles north of Mesa.
A handgun was discovered but no more explosives were located as of Tuesday afternoon, said Sgt. Brandon Jones, a sheriff's spokesman. Agents with the FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives were assisting with the desert search.
Authorities late Monday detonated what appeared to be live hand grenades found at a site in the Tonto National Forest. Jones said the items were in an ammunition canister.
Hikers who reported finding the grenades also found several canisters with ammunition for guns.
Jones said there also was a map indicating there may be more explosives in 20 additional locations in the same area.
Grenades have become a concern as authorities deal with drug traffickers along the Arizona border, but Jones said the desert region that was searched is a popular shooting area.
Authorities don't believe the situation had any ties to terrorism.
``As of now, it is not yet known who or why someone would place these devices, guns and ammunition,'' Jones said.
He declined to talk about the map that was found because it's part of an ongoing investigation.
``It's making investigators concerned enough to go search those spots,'' Jones said, describing the operation as ``an Easter egg hunt, if you will.''
Jones said deputies would be searching the other locations noted on the map.