There was no immediate claim of responsibility.
Border guards have come under attack in the past from the Islamist group Al-Qaeda in Kurdistan -- formerly Ansar al-Islam -- which operates in the region.
Also today, at least four civilians died when a car bomb exploded in central Baghdad, and three police officers were killed in clashes west of the southern city of Al-Nasiriyah.
In Al-Aziziyah, south of Baghdad, gunmen burst into the home of a local councilor and killed his wife and son. A Turkish driver was also killed in northern Iraq.