Casualties from the battle for Tripoli mounted on Tuesday as a group loyal to Islamic State killed three people in Libya's remote centre showing how militants may exploit renewed chaos.
The United Nations' health body said local facilities had reported 47 people killed and 181 wounded in recent days as eastern forces seek to take Libya's coastal capital from an internationally-recognised government.
That was a higher toll than numbers given by either side, and appeared to be mainly fighters, although it also included some civilians including two doctors, World Health Organisation (WHO) spokesman Tarik Jasarevic told a Geneva news briefing.
The eastern Libyan National Army (LNA) forces of Khalifa Haftar - a former general in ousted leader Muammar Gaddafi's army - seized the largely desert south earlier this year before heading to Tripoli this month, where they are ensconced on the southern side.
The government of Prime Minister Fayez al-Serraj, 59, is seeking to block them with the help of armed groups who have rushed from Misrata in pickup trucks fitted with machine guns.
The United Nations, United States, European Union and G7 bloc have all appealed for a ceasefire and return to a U.N. peace plan, but Haftar has so far not heeded them.
Far south of Tripoli, a group loyal to the Islamic State (IS) attacked the town of Fuqaha, killing three people and kidnapping another before leaving, residents said.
Fuqaha is controlled by fighters loyal to Haftar, who casts himself as a foe of Islamic extremism though he is also viewed by opponents as a new dictator in the mould of Gaddafi.
IS has been active in Libya in the turmoil since the Western-backed overthrow of Gaddafi eight years ago.
It took control of the coastal city of Sirte in 2015 but lost it late in 2016 to local forces backed by U.S. air strikes, and now operates in the shadows.
Libya's potential slide into civil war threatens to disrupt oil supplies, boost migration across the Mediterranean to Europe and scupper U.N. plans for an election to end rivalries between parallel administrations in east and west.
Libya has become the main conduit for African migrants and refugees trying to reach Europe, many of whom suffer torture, rape and extortion on their journeys.
Those who manage to board a boat to Italy risk drowning or being sent back into detention in inhumane conditions, according to the U.N. migration agency, which estimates that twice as many die in the Sahara desert as in the Mediterranean.
The U.N. refugee agency said it was extremely concerned about the rapidly deteriorating situation, and thousands of refugees and migrants were trapped in detention centres in the conflict areas.
On Monday, a warplane took out Tripoli's only functioning airport, and the number of displaced - 3,400 at the last U.N. count - is mounting alongside the casualties.
U.N. officials said they were also concerned migrants could be used as human shields or forcibly recruited to fight.
"The people of Libya have long been caught between numerous warring parties, with some of the most vulnerable suffering some of the gravest violations of their human rights," U.N. Human Rights High Commissioner Michelle Bachelet said.
"I appeal to all sides to come together to avoid further senseless violence and bloodshed."