U.S. and ukrainian spy agents arrested in Serbia

Two U.S. and two Ukrainian citizens have been arrested in Serbia for trying to photograph the military security headquarters in downtown Belgrade with a drone.

A Serbian state TV report Monday did not identify the four or give details, saying only that the two Ukrainians are women and that they are all in police custody.

Another American was arrested in Serbia earlier this month for possession of an unmarked gun. Pro-government media alleged that he was a former Navy SEAL and had planned the assassination of unidentified Serbian officials.

Serbian President Aleksandar Vucic on Sunday mentioned the arrest of a "group" of foreigners, but added that their case is "nothing especially serious."