North Korea fired seven surface-to-air missiles into the East Sea on Thursday amid U.S.-South Korea Key Resolve military exercises, South Korea’s Joint Chief of Staff (JCS) told media on Friday.

The launches, which come on the last day of the joint exercises, follow two North Korean short-range ballistic missile launches that coincided with the beginning of the drills earlier in the month.

“The North Korean military fired multiple rounds of ground-to-air missiles into the East Sea from Seondok, South Hamkyong Province, at around 6-7 p.m. yesterday,” the JCS said according to Yonhap News Agency.

Yonhap, which quoted an anonymous source