North Korea test-fired two more ballistic missiles on Sunday, this time using the border city of Kaesong as the launch site.

The missiles were believed to Scud variants with a range of 500 kilometers (about 311 miles) launched between 1:20 and 1:30 a.m. Korean time, a South Korean military official told AP. The firing follows a Scud launch on June 29 and KN-09 tests on June 26 and July 2.

What made Sunday’s launch unusual was the venue, as Kaesong is the site of the joint-Korean Kaesong Industrial Complex, a symbol of cooperation between Seoul and Pyongyang. North Korea typically