North Korea fired two short-range ballistic missiles off its east coast on Monday, South Korea's military said, in an apparent response to ongoing joint military drills involving South Korea and the United States.

South Korea's Joint Chiefs of Staff said the two missiles were fired from the North Hwanghae Province area, with the first detected around 7:47 a.m. and the second around 8 a.m. Each flew about 370 kilometers, it said.

The launches came as the U.S. aircraft carrier Nimitz is set to join exercises with the South Korean navy in open waters south of Jeju Island on Monday, and a day before the warship is scheduled to arrive at a port in the southern South Korea city of Busan.

North Korea has vehemently protested recent joint military exercises carried out by South Korea and the United States, including the 11-day Freedom Shield exercise through last Thursday. It was the first large-scale springtime military drill in five years.

An amphibious landing exercise between the allies' militaries called the Ssangyong exercise is under way and will run through April 3.

The Japanese government said the projectiles are believed to have fallen in the sea outside of its exclusive economic zone.

There were no reports of damage to aircraft or ships, according to the government.

North Korea said Friday it test-fired four cruise missiles of two different types two days earlier, with leader Kim Jong Un warning Seoul and Washington they should stop "reckless" anti-North Korea war drills, according to the official Korean Central News Agency.

It also said it tested earlier last week a new underwater nuclear attack drone it claims can generate radioactive tsunami to destroy enemy ships and ports, according to state-run media.

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