SEOUL, South Korea — North Korea launched multiple cruise missiles toward the sea on Wednesday, South Korea’s military said, three days after the North carried out what it called a simulated nuclear attack on South Korea.

The launches are the North’s fourth round of weapons tests since the U.S. and South Korean militaries last week began large-scale military drills that the North views as an invasion rehearsal.

The 11-day U.S.-South Korean military drills are to end on Thursday. But North Korea is expected to continue its testing activities as the United States reportedly plans to send an aircraft carrier in coming days for another round of joint drills with South Korea.

South Korea’s Joint Chiefs of Staff said it detected “several” cruise missile launches made from the North’s northeastern coastal town of Hamhung. It said the missiles flew into the North’s eastern waters and that South Korean and U.S. intelligence authorities were analyzing further details.

The Joint Chiefs of Staff said the South Korean military will maintain a firm readiness and successfully complete the rest of the drills with the United States.

U.N. Security Council resolutions ban North Korea from launching ballistic missiles but don’t prohibit its cruise missile tests. But experts say cruise missiles developed by North Korea also pose a serious threat to its neighbors, as they are designed to fly at a lower altitude to avoid radar detection. The North has described the cruise missiles it recently tested as “strategic,” communicating an intent to arm them with nuclear weapons.

Coming off a record year in testing activity, the North has extended its provocative run in weapons demonstrations in 2023, launching around 20 missiles in 10 separate events. The weapons that were tested included short-range nuclear-capable ballistic missiles capable of striking South Korea and intercontinental ballistic missiles designed to attack the mainland U.S.

Wednesday’s launches were the North’s first tests of cruise missiles since March 21, when it said it fired two cruise missiles from a submarine. Last month, North Korea launched what it called four long-range cruise missiles that demonstrated potential ranges to strike targets 2,000 kilometers (1,240 miles) away.

On Sunday, North Korean leader Kim Jong Un supervised a test-firing of a short-range ballistic missile that was launched from what was possibly a silo dug into the ground. North Korea’s state media called the launch a simulated nuclear attack on unspecified South Korean targets.