The United States and South Korea hold a joint military exercises . Hide Caption 8 of 10 Photos: Pyongyang says that constitutes a grave provocation . South Korea says the flag was to mark territory and was not used as a target .
The United States and South Korea hold a joint military exercises . A North Korean flag is used in the live-fire drills . Pyongyang says that constitutes a grave provocation . South Korea says the flag was to mark territory and was not used as a target .