The assault left two security guards dead and another injured, according to the statement by the South Korean Foreign Ministry, quoted by The New York Times.
Islamic State-affiliated militants have reportedly claimed the responsibility for the attack via social media.
The Foreign Ministry statement said that the perpetrators fired machine gun rounds from a car. No South Korean staff appear to have been hurt in the attack.
Libya has been in crisis since long-term leader Muammar Gaddafi was overthrown in 2011 and a civil war erupted.
There are two rival governments in the country, one in Tripoli and one in the city of Tobruk. The forces of the internationally recognized Libyan government in Tobruk are fighting numerous rebel groups, including militants linked to the Islamic State.
