(CNN) -- Seven members of the Mexican military were found inside the United States on Friday, telling border agents they had become disoriented while on patrol and accidentally crossed into the country, the U.S. Customs and Border Patrol said.

The incident began about 8 a.m. Friday, when the Border Patrol's Yuma, Arizona, sector was notified that a military-style Hummer was broken down, Customs and Border Patrol said in a written statement.

Agents said they found the vehicle about 200 yards from the Colorado River, and the seven individuals were dressed in military-style clothing. Customs and Border Patrol later determined that the troops' entry was unauthorized.

U.S. agents told the Mexican troops they were inside the United States and "peaceably" took them into custody, the statement said. "At no time were any hostilities exchanged between the agents and military officials." Watch how Mexican troops found their way in the United States »

The Hummer was equipped with a turret-mounted machine gun, the Border Patrol said.

According to Customs and Border Patrol, the soldiers were assigned to the 23rd Regiment Motorized Cavalry of the Mexican Army. The soldiers said they believed that they were still in Mexico because they remained on the south side of a newly constructed border fence.

"The soldiers, weapons and vehicle were placed in Border Patrol custody and transported to the CBP San Luis, Arizona, Port of Entry, where each of the subjects was processed in accordance with Border Patrol policy," the statement said. None of the seven had any criminal or immigration history, the agency said.

The soldiers, weapons and vehicle were repatriated and "remanded into the custody of their commanding officer," the Border Patrol said. The incident remains under investigation, however, and the Border Patrol's Office of Internal Affairs was notified, the statement said.

"This is not an uncommon occurrence," Rep. Tom Tancredo, R-Colorado, told CNN. "Often times, it is the result of the Mexican military providing cover essentially for drug transportation across into our country, and/or creating a diversion so it will draw our people away from the place where the drugs are coming across."

In August, the Border Patrol said Mexican troops had crossed the border illegally 42 times since October 2007.

Tancredo said the U.S. State Department lodged a complaint with the Mexican government for the first time over the military incursions a few weeks ago. Attempts to contact the State Department and the Mexican government Friday were unsuccessful.

CNN's Casey Wian contributed to this report.

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