North Korea says it conducted a tactical nuclear strike exercise and launched two ballistic missiles on Wednesday in response to joint military drills being held by the United States and South Korea.

The General Staff of the Korean People's Army said that it fired the missiles northeastward from Pyongyang International Airport. The announcement was carried by the ruling Workers' Party newspaper Rodong Sinmun on Thursday.

It said the tactical nuclear strike exercise simulated the destruction of South Korea's major command centers and operational airfields. It also said the missiles were detonated at an altitude of 400 meters above the target island.

The Rodong Sinmun carried a photo of a missile believed to be a solid-fuel type being fired from a mobile launch pad on a runway. Solid-fuel missiles are a type that can be launched swiftly. There was also a photo of a missile exploding over an island.

North Korea's military said Wednesday's drill was in response to the joint drills by the US and South Korea involving US B-1B bombers the same day. It said it would never sit back and watch the "reckless actions" of the US and South Korean militaries.

South Korea's military said the North fired two short-range ballistic missiles from an area in or around Sunan, near Pyongyang, late Wednesday. The North's announcement is believed to be referring to these launches.