Mexican authorities have detained six Iraqi citizens who they believe intended to cross into the United States from Tijuana.
The five men and one woman claimed to be German citizens when they arrived at the Tijuana airport Tuesday night on a flight from Mexico City.
Immigration authorities sent the Iraqis back to Mexico City for questioning.
Officials were trying to determine whether the Iraqis might be Chaldean Christians, a group which claims it faces persecution in Iraq.
Chaldean Christians often seek U.S. asylum, but many say these requests have been complicated by security concerns in the United States.
Mexican authorities were investigating whether the Iraqis might have violated Mexican immigration laws.