NEW : North Korea fully reopens its border to South Koreans without explanation . Pyongyang closed on March 9 because of U.S.-S. Korea military cooperation . Border partly opened Monday , allowing 300 South Koreans daily to go home . The South Koreans mostly work at joint industrial complex in border town Kaesong .
NEW : North Korea fully reopens its border to South Koreans without explanation . Pyongyang closed border March 9 because of U.S.-S. Korea military exercises . Border partly opened Monday , allowing 300 South Koreans allowed to go home . Stranded S. Koreans mostly work at joint industrial complex in border town Kaesong .