Unknown gunmen on Sunday attacked the South Korean embassy in Libya's capital Tripoli, leaving two guards dead and one wounded, according to security sources.The armed group traveling in a car fired a hail of bullets in front of the embassy compound, security officer Mabrouk Abu-Bakr told Xinhua news agency.He said the attack was mounted by the Islamic State terrorist group, but he did not elaborate on the motives of the attack.Tripoli fell to the armed Islamist coalition Libya Dawn last August, when the internationally recognised Libyan government retreated to the eastern town of Tobruk. The city has been plagued by bomb attacks, assassinations and kidnappings.Several embassies, including those of Egypt and the United Arab Emirates, have been targeted by militants in similar attacks.