NEW : The U.S. Embassy says it 's aware of reports the man was trying to swim to Koreas . A marines official says not immediately clear if the man was attempting to cross the border . Three U.S. citizens are currently in detention in North Korea : He was caught on the bank of the North where it divides the Three Koreas .
NEW : The U.S. Embassy says it 's aware of reports the man was trying to swim to Koreas . A marines official says not immediately clear if the man was attempting to cross the border . He was caught on the bank of the North where it divides the Three Koreas .