Two detained in Mexico for U.S. Border Agent Shootings.

 MEXICO CITY - Mexican troops arrested two men on Wednesday suspected of involvement in the killing of a U.S. Border Patrol agent shot dead in Arizona while responding to a tripped ground sensor, Mexican security officials said.
The agent who died was among three who were patrolling on foot about 5 miles north of the international border when gunfire erupted well before daybreak on Tuesday. A second agent was also wounded while the third, a woman, was unharmed.
The agents involved in the incident had been patrolling in an area near the border town of Naco, well-known as a corridor for smuggling, and the Cochise County Sheriff's department has said that tracks were found heading south after the shooting.
The two suspects detained in Mexico were arrested in a Mexican military operation in the city of Agua Prieta, in Mexico's northern Sonora state, a few miles from the spot where Nicholas Ivie, 30, was shot dead, a Mexican Army officer, who declined to be named, told Reuters.
A Mexican police official in Naco, across the border from the Arizona town of the same name, confirmed the arrests, which occurred in the early hours of Wednesday.
The killing marked the fourth death of a Border Patrol agent in a violent confrontation in Arizona in less than two years and reignited concerns about border security in a state that is already at the forefront of the national immigration debate.