The Unification Ministry says it allowed some 70 employees of South Korean firms to enter the Gaeseong Industrial Complex in North Korea on Monday.

It marked the first time for the ministry to allow South Korean employees to enter the North since Pyongyang staged an artillery attack on South Korea’s Yeonpyeong Island on November 23rd.

Ministry spokesman Chun Hae-sung said the group of workers will take over for South Koreans who have been working and residing at the industrial complex for an extensive time.

The ministry banned visits by South Korean employees to the industrial park shortly after the North’s artillery attack due to safety concerns. Since the North’s attack, Seoul has only allowed vehicles carrying fuel and food for South Koreans residing in the industrial park to enter the North.

According to the ministry, there are currently 333 South Korean workers residing in the North, which is less than half the number of South Koreans who were in the communist state prior to the North’s artillery attack.