The Unification Ministry in Seoul has permitted companies operating at the Gaeseong Industrial Complex in North Korea to increase their staff numbers.

The ministry said Thursday that a total of around 700 South Korean workers can be employed at the Gaeseong firms, which is about 100 more than before.

The measure follows calls by the companies to lift the restrictions on employee levels at Gaeseong.

However, the firms remain disgruntled considering that 121 South Korean companies are based at the complex, so an increase of 100 people translates into about one person per firm.

Following the attack on the "Cheonan" warship, Seoul halved the number of South Korean Gaeseong workers to 500 in May.