YUMA, Ariz. (AP) _ The increasing success of U.S. Border Patrol detection networks may be forcing illegal aliens deeper into the desert where their survival often depends on the rescue efforts of the same agency, a sheriff says.

Law enforcement officers rescued 22 aliens believed to have entered this country illegally over the weekend, but three others died.

''Lord knows how many bodies are still out there. We don't know,'' Yuma County Sheriff John Phipps said Wednesday.

Twenty-five men and teen-agers - all thought to be Mexican nationals - crossed the border Saturday near Los Vidrios, about 80 miles east of San Luis, Sonora, said Al Saucier, assistant chief of the U.S. Border Patrol's Yuma sector.

Before two of them were spotted Monday, the men had resorted to drinking urine and sucking moisture from cacti and toothpaste to stay alive. One cut his throat in desperation but survived.

Two members of the band were charged Wednesday with conspiracy to smuggle aliens.

Saucier identified them as Julio Parada Salazar, 31, of Ixtlan del Rio, Nayarit, Mexico, and Victor Lopez Basua, 36, Culiacan, Sinaloa, Mexico. Saucier said additional charges might be filed through the U.S. attorney's office in Phoenix following investigation of the deaths.

The dead were identified as Bernardo Martinez, 19, of Rancho San Luis, near Acambaro, Guanajuato; Sergio Lopez Duran, 17, El Rancho de la Mesa, Guanajuato; and Antonio Vega, no age or hometown available.

Martinez and Lopez, the son of a 62-year-old who survived the ordeal, were dead when found, and Vega died aboard a helicopter en route to Yuma Regional Medical Center, Saucier said.

Authorities believe Parada was a guide and that Lopez was brought along to drive the men into California after they reached Interstate 8 near Dateland.

The aliens were told they faced a walk of four to seven hours, Saucier said. In reality, they were embarking on a 50-mile hike over rugged terrain under a scorching sun.

Each set out with one gallon of water, he said. Authorities say an individual typically loses half a gallon of body water per hour while trudging through the desert heat.

Saucier said some of the men had paid $350 to $400 to be smuggled into the United States and that others had promised to pay after they obtained work as agricultural laborers.

Phipps said he believes greater numbers of illegal aliens are trying to sidestep such points as San Luis and Nogales, where the Border Patrol has grouped batteries of video cameras and other sensory devices. Saucier said he doubted that theory.

''In Yuma, you can make an entry into the United States and be on a railroad heading west in 15 minutes or half an hour ... and even though you're likely to be picked up, there's a possibility you can make it if you keep trying,'' Saucier said. ''I still believe they will continue to try in an area where it's the easiest.''

The deaths were the first in Arizona this year among desert-crossing aliens, Saucier said.

In the last seven years about 70 people have died, including 13 in July 1980 when a group of nearly 30 Salvadorans attempted a 40-mile hike across Organ Pipe Cactus National Monument.

Saucier said the Border Patrol's forays into the desert are as much missions of mercy as attempts to arrest aliens.

''We found eight bodies in the desert last year, but we also rescued a total of 56. We apprehend people, yes, but we also rescue them, and in some cases we rescue people who never would have made it. In this case, there's no question that we would have had 25 dead,'' Saucier said.