South Korea's Joint Chiefs of Staff(JCS) said that North Korea fired two short-range ballistic missiles toward the East Sea on Thursday.

The JCS said that it detected the missiles were fired from the Samsok area in Pyongyang between 6:01 a.m. and 6:23 a.m.

The JCS said that the first missile traveled about 350 kilometers at a speed of Mach Five with an altitude of some 80 kilometers, while the second flew about 800 kilometers at a speed of Mach Six with an altitude of some 60 kilometers.

The intelligence authorities of South Korea and the U.S. are conducting a detailed analysis of the launch.

JCS Chairman Kim Seung-kyum had discussions with the United States right after the launch and reaffirmed that South Korea and the U.S. will further solidify their defense readiness in the face of any threats or provocations by the North.

The South Korean military strongly condemned the North's recent series of ballistic missile launches as a grave act of provocation that undermines stability on the Korean Peninsula and in the international community. It urged the North to immediately stop the launches, calling them a clear violation of the UN Security Council resolutions.

The launch, the sixth in 12 days, came two days after the North fired an intermediate-range ballistic missile over Japan from the area of Mupyong-ri in Chagang Province, and appears to be a response to the redeployment of a U.S. nuclear-powered aircraft carrier to the eastern waters of South Korea.

Tensions around the Korean Peninsula have escalated amid the North's series of launches, joint drills by South Korea and the U.S. and the return of the USS Ronald Reagan to the East Sea for additional joint exercises with South Korea and Japan in response to Tuesday's missile launch.