This photo released by North Korea's state-run Korean Central News Agency (KCNA) on Aug. 10, 2017, shows North Korea test firing a short-range ballistic missile (SRBM). Yonhap

North Korea fired two short-range ballistic missiles (SRBMs) toward the East Sea on Sunday, the South Korean military said, after Seoul and Washington wrapped up a naval exercise, involving a U.S. aircraft carrier, the previous day.

The Joint Chiefs of Staff (JCS) said it detected the launches from the Munchon area in Gangwon Province between 1:48 a.m. and 1:58 a.m., and that the missiles flew some 350 kilometers at apogees of around 90 km at top speeds of Mach 5.

Given the distance and altitude, the projectiles are presumed to be "super-large caliber" missiles, fired from a multiple rocket launch system, known as the KN-25, according to observers in Seoul.

The launch, the North's seventh missile provocation in two weeks, followed the conclusion of the South Korea-U.S. exercise, involving the USS Ronald Reagan carrier, on Saturday and of the allies' trilateral drills with Japan on Thursday.

It also came on the eve of the 77th anniversary of the founding of the North's ruling Workers' Party.

"The recent series of North Korea's ballistic missiles is an act of significant provocation that undermines peace not only on the Korean Peninsula but also in the international community, and a clear breach of U.N. Security Council resolutions," the JCS said in a text message sent to reporters.