Libya's landline phone system broke down in much of the country after unknown people damaged submarine cables in an area held by Islamic State, officials said on Wednesday, in another sign of state collapse.
Libya is in chaos with two governments allied to armed groups fighting for control four years after the ousting of Moammar Gadhafi, while Islamic State has expanded by exploiting a security vacuum in the region.
The chaos has reduced oil, gas and electricity production to a trickle, disrupted the import of wheat, food and hospital drugs and scared away foreign embassies and airlines.
The telecommunications ministry in Tripoli said land phone connections in the eastern and southern regions stopped "due to deliberate acts against a submarine cable station in Sirte," a western city on Libya's Mediterranean coast.
It did not say who was responsible for the damage, adding that the lack of security made it impossible to fix the damage.
Tripoli residents trying to call people in the eastern part of the nation did not get a connection on the landline. Sirte is controlled by Islamic State militants who have gained a foothold in several parts of the North African country.
Libya's two rival governments have repeatedly flown airstrikes against the group in Sirte.
The official government fled to the east a year ago after a rival faction seized Tripoli, setting up its own administration.
Neither administration controls much territory, allowing Islamists, tribesmen or other armed groups to carve out their fiefdoms.
The country's conflict is funded by oil revenues distributed among the warring factions, a system set up by the state after Gadhafi's ousting in a failed bid to buy the loyalty of former rebel groups.
Cell phone networks also have deteriorated during the conflict, with power outages and spare parts contributing to interruptions in services, especially in remote towns.