Mexican commandos have discreetly traveled to the United States, assembled at designated areas and dispatched helicopter missions back across the border aimed at suspected drug traffickers. The Drug Enforcement Administration provides logistical support on the American side of the border, officials said, arranging staging areas and sharing intelligence that helps guide Mexico’s decisions about targets and tactics.

Officials said these so-called boomerang operations were intended to evade the surveillance — and corrupting influences — of the criminal organizations that closely monitor the movements of security forces inside Mexico. And they said the efforts were meant to provide settings with tight security for American and Mexican law enforcement officers to collaborate in their pursuit of criminals who operate on both sides of the border.