SEOUL, South Korea (AFP) — North Korea fired two ballistic missiles into the sea early Sunday, Seoul's military said, the seventh such launch in two weeks, just hours after a nuclear-powered United States aircraft carrier wrapped up joint drills off the Korean peninsula.

Seoul, Tokyo and Washington have ramped up combined naval exercises in recent weeks, infuriating Pyongyang, which sees them as rehearsals for invasion and justifies its blitz of missile launches as necessary "countermeasures."

South Korea's military said Sunday it had "detected two short-range ballistic missiles between 0148 and 0158 fired from the Munchon area in Kangwon province towards the East Sea," referring to the body of water also known as the Sea of Japan.

The missiles "flew approximately 350 kilometers at an altitude of 90 kilometers," Seoul's Joint Chiefs of Staff said in a statement, calling the launches a "serious provocation."

Tokyo also confirmed the launches, with the coast guard saying the missiles had landed outside Japan's exclusive economic zone.

Japanese senior vice defense minister Toshiro Ino said Tokyo was analyzing the missiles, adding that "either one of them has the possibility of being a submarine-launched ballistic missile."

Seoul said last month it had detected signs the North was preparing to fire an SLBM, a weapon Pyongyang last tested in May.

The US military's Indo-Pacific Command said in a statement that they were "consulting closely with our allies and partners," adding that the launch highlighted the "destabilizing" nature of North Korea's missile programs.

With talks long stalled, Pyongyang has doubled down on its banned weapons programs, firing an intermediate range ballistic missile over Japan last week, with officials and analysts warning it has completed preparations for another nuclear test.