On Thursday , a North Korean fishing boat was seized following an alleged incursion into South Korean waters , and then returned with its three crew members to the following day . North Korean military exercises see shelling into South Korean waters ; South responds with artillery fire . North warned South it will conduct military exercises off the country 's western coast . North also hints at further nuclear tests . This came soon after North 's test - firing of medium - range missiles into the sea .
North Korean military exercises see shelling into South Korean waters ; South responds with artillery fire . North warned South it will conduct military exercises off the country 's western coast . North also hints at further nuclear tests . This came soon after North 's test - firing of medium - range missiles into the sea .