TUCSON - Gunmen stopped a pickup truck full of illegal immigrants, shot several and took the rest captive Thursday in an attack that left at least three men dead.
Authorities were trying to determine who the gunmen were and what happened to another two or three people believed still missing.
The men shot three people, one fatally, along a known smuggling corridor near Tucson, then forced the six or seven other immigrants in the group to leave with them, Pima County sheriff's officials said.
The bodies of two of the immigrants were found about 10 miles north in the cab of the pickup truck that had been carrying the group. The other immigrants had not been found by midafternoon Thursday.
The incident occurred on the Ironwood Forest National Monument, and "the method of operation was similar" to a robbery Wednesday night more than 70 miles south, near the border at Sasabe, said Rick Kastigar, the Pima County sheriff's criminal investigations chief.
In that incident, four Spanish-speaking men carrying AK-47 assault weapons and dressed in dark clothing and ski masks confronted and robbed 18 immigrants, Kastigar said. No one was reported injured in Wednesday night's robbery, he added.
Investigators did not immediately know a motive for Thursday's attack, but gangs of bandits are known to roam border areas preying on illegal immigrants as they cross into the country.
"We're thinking it was possibly that they were attacked by bandits," sheriff's spokesman Sgt. Jim Ogden said.
Feuding among smuggling organizations also is not uncommon, sometimes involving demands for ransoms from the immigrants' relatives to gain their freedom.
Two men who were not injured were in custody and were telling deputies what happened, Kastigar said.
Thursday morning's attack occurred on a dirt road near the Silverbell Mine, about 20 miles northwest of Tucson, Kastigar said.
Kastigar said the immigrants were heading north when four men armed with assault rifles in another vehicle forced the truck to stop. During the confrontation, one man was killed, another was shot in the hand - losing several fingers - and a woman was shot in the chest and also sustained a neck injury, Kastigar said.
Ogden said the two wounded immigrants were taken to a hospital with "very, very serious injuries."
"We still believe a couple of people are unaccounted for," Kastigar said. "There have been similar cases where undocumented migrants have been taken to a location and relatives in Mexico contacted and extortion took place.
"This is speculation on my part," he added.
Border Patrol, Immigration and Customs Enforcement and Bureau of Land Management agents were assisting in the investigation.