SEOUL, South Korea — North Korea fired several ballistic missiles into the sea on Monday, South Korea’s military said, hours after South Korean and U.S. troops kicked off their large annual combined drills, which the North views as an invasion rehearsal.

South Korea and the United States have begun their annual joint military exercises, but they paused live-fire training while Seoul investigates how two of its fighter jets mistakenly bombed a civilian

Under UN Security Council Resolutions, North Korea is barred from staging any launches that use ballistic missile technology