Seoul: North Korea fired two medium-range ballistic missiles into the East Sea on Sunday, the South Korean military said, the latest in a series of launches that raised tensions on the Korean Peninsula.

The Joint Chiefs of Staff (JCS) said that it detected the launches from the Tongchang-ri area, North Pyongan Province, between 11:13 am and 12:05 pm The missiles, fired at steep angles, flew some 500 kilometers, it added, as reported by Yonhap news agency.

It said the missiles were fired about 50 minutes apart but gave no further details, like precisely what type of weapons North Korea fired and how far they flew.

The Joint Chiefs of Staff said South Korea’s military has bolstered its surveillance posture and maintains a readiness in close coordination with the United States.

The JCS denounced the launches as an act of “significant provocation” that undermines peace and stability not only on the Korean Peninsula but also in the international community, and a “clear” breach of UN Security Council resolutions.

“We strongly condemned them and urge the North to immediately stop them,” it said in a text message sent to reporters.

It added the South Korean military will maintain a solid readiness posture based on its capabilities to respond “overwhelmingly” to any North Korean provocations.

The Tongchangri area is home to North Korea’s Sohae Satellite Launching Ground, where the country in past years launched satellite-carrying long-range rockets in what the U.N. called a disguised test of ICBM technology.

Sunday’s launch followed the North’s commemoration on the previous day of the 11th anniversary of the death of Kim Jong-il, the former leader and father of current leader Kim Jong-un, the report said.

This year, the North has fired more than 60 ballistic missiles, marking a single-year record, it added.