North Korea fired two ballistic missiles into the sea off the eastern coast of the Korean peninsula on Sunday, South Korea and Japan said, prompting South Korea’s presidential office to “strongly condemn” Pyongyang over the escalation of tension.

According to South Korea’s Joint Chiefs of Staff, the two medium-range missiles flew about 500 kilometers.

Japanese Deputy Defense Minister Toshiro Ino said the missiles appeared to have fallen outside Japan’s exclusive economic zone (EEZ) and there were no reports of damage.

“North Korea’s ballistic missiles were launched at steep angles and landed in the East Sea,” South Korea’s JCS said in a statement.

“South Korean and U.S. intelligence officials are conducting a thorough analysis, taking into account recent trends related to North Korea’s missile development.”

South Korea convened a National Security Council (NSC) meeting on North Korea’s missile launch and “strongly condemned” the escalation of tension on the Korean peninsula, South Korea’s presidential office said in a statement.

The presidential office added that the North’s continued provocations and the development of nuclear weapons and missiles would further endanger the North Korean regime.

The North’s missile launch comes just days after the country tested a high-thrust solid-fuel engine that experts say would allow for faster and more mobile ballistic missile launches, in its bid to develop a new strategic weapon and accelerate its nuclear and missile programs.

The test, overseen by leader Kim Jong Un, was carried out on Thursday at North Korea’s Sohae satellite launch base, which has been used to test missile technologies, including rocket engines and space launch vehicles, the official KCNA news agency reported on Friday.

North Korea has conducted an unprecedented number of missile tests this year, including an intercontinental ballistic missile (ICBM) capable of reaching U.S. territory, despite international bans and sanctions.