Militants stormed on Friday the Tunisian consulate in the Libyan capital Tripoli, taking 10 members of the consulate hostage, the Tunisian Foreign Ministry said.
In a statement, the Tunisian Foreign Ministry said the incident was "a cowardly violation of Tunisian sovereignty, international conventions, and diplomatic traditions which guarantee the security of diplomats and consulate employees."
No group has claimed responsibility for the attack yet.
The ministry urged Tunisian nationals not to travel to Libya. Official figures show around 60,000 Tunisians are working in the country.
Tunisia is one of the few countries with embassies still open in Tripoli. In July, French and British nationals left the country amid deteriorating security situation.
Libya has been in turmoil since the fall of Muammar Gaddafi in 2011. Rival militant groups fight for greater dominance, which has plagued the country so far.
In April, a bomb exploded outside the entrance of the Moroccan embassy and gunmen opened fire on the South Korean embassy, killing a security guard.
Meanwhile, ISIS group (ISIS) seized on Tuesday Sirte, a northern coastal city where Gaddafi was born, expanding its territories beyond Syria’s Raqqa, its stronghold.
Libya is currently divided between two parliaments, the General National Council (GNC) in the capital of Tripoli, which was founded with the help of the United States and France, and the House of Representatives (HoR) body, which was founded last August.