A Mexican man pleaded guilty Thursday to running an organization that smuggled illegal immigrants through a live bombing range in southeastern California.

Javier Sanchez Perfino, 30, acknowledged running a group that smuggled people from Mexico through the Chocolate Mountain Aerial Bombing and Gunnery Range, where U.S. pilots are trained before going to war in Afghanistan. The migrants were eventually taken to Los Angeles.

Prosecutors say the ring also paid two seasoned U.S. Border Patrol agents to release illegal immigrants from federal custody, but Sanchez was not charged with that crime. The two agents pleaded guilty in 2006 to taking about $180,000 between them.

Smugglers are drawn to bombing ranges in the area because immigration authorities avoid them, said Jeffrey Calhoon, chief of the Border Patrol's El Centro, California, sector.

Border Patrol agents instead rely on sensors to alert them to traffic and make arrests when the migrants leave the range, Calhoon said. If agents think lives are endangered, they enter the range after calling military authorities to suspend bombing.

"It's possible that there's quite a bit of unexploded ordnance out on the range," he said.

No migrants have been reported killed from bombs, said Border Patrol spokesman Quinn Palmer.

Sanchez, a legal U.S. resident, faces up to 10 years in prison when he is sentenced Dec. 5 for smuggling illegal aliens for financial gain and conspiracy to smuggle from January 2003 to October 2006.

"Culpable," he said in Spanish after U.S. District Judge Jeffrey Miller outlined the charges against him. His attorney, John Lemon, declined to comment after the hearing.

Authorities have said the organization smuggled 60 to 80 people a day at its peak, charging $1,500 a person.