The U.S. Border Patrol said agents encountered the troops in a Humvee a short distance north of the border near Yuma, in far west Arizona, early on Friday.
'The Border Patrol agents on scene established a dialogue with the subjects, who identified themselves as members of the Mexican military,' the Border Patrol said in a news release.
'The ... agents informed them of their presence within the United States. Upon notification, the subjects were peaceably taken into custody,' it added.
The soldiers, who were assigned to the 23rd Regiment Motorized Cavalry of the Mexican Army, said they had become disoriented while on patrol and had accidentally crossed the international boundary, the Border Patrol said.
After relieving them of their arms, agents took the soldiers to the San Luis, Arizona, port of entry where they were processed and repatriated to Mexico, along with their weapons and vehicle.
The incursion was the second by Mexican troops in recent months.
In August, a group of four Mexican soldiers briefly held a U.S. Border Patrol agent at gunpoint in a remote stretch of the Arizona desert after they mistakenly strayed north across the border.
(Reporting by Tim Gaynor, editing by Eric Beech)
