About 100 illegal immigrants were rescued from the desert about 50 miles west of Phoenix, many suffering from dehydration and exhaustion after triple-digit heat.

Seven immigrants and three sheriff's deputies were taken to hospitals after the rescues late Tuesday, said Maricopa County Sheriff Joe Arpaio. Officers used a helicopter, canine units, all-terrain vehicles and foot patrols to find them.

The immigrants told authorities that three people had died, but Kempher said no bodies had been found.

Click here to visit FOXNews.com's Immigration Center.

Deputies were pulled out of the desert when night fell, said sheriff's Sgt. Jim Kempher. They left water behind and posted some deputies in the area until the search could resume later Wednesday for any more immigrants.

Arpaio, whose office made the discovery, said investigators suspect the immigrants were left in the area until smugglers could arrange for transportation elsewhere.

"They are stashing them out there," Arpaio said.

Authorities gave water to the immigrants, who were being turned over to federal immigration authorities, Arpaio said.

Some immigrants said they hadn't had water since Sunday, said Lt. Chuck Siemens, who was in charge of the search operation. "They were bombarding us for water. We passed out water bottles, and it was a frenzy," he said.

The state has a new anti-immigration law, passed amid frustration over Arizona's porous border with Mexico and the costs of health care and education for illegal immigrants. Immigration is usually a federal responsibility.

The immigrants found Tuesday won't be arrested, Arpaio said. They weren't caught in the act of being transported by a smuggler — a necessary element of proving the state crime.

"We are now zeroing in on the smugglers," Arpaio said.

Maricopa County, which includes Phoenix, is Arizona's most populous county.

Click here to visit FOXNews.com's Immigration Center.