ISIS extremists have taken advantage of the battle for Tripoli to attack a remote city in Libya's central desert, killing the local council president and kidnapping the head of the municipal guards.
Three men were killed and several buildings set ablaze in the attack on the town of Fuhaqa, 600 kilometres south-east of Tripoli.
It is the first major attack by ISIS in Libya since the same town was attacked, with five killed, in October last year.
Diplomats fear the chaos caused by the battle for Tripoli has drawn security forces away from other parts of the country.
Fuhaqa is controlled by groups aligned to Field Marshal Khalifa Haftar’s Libyan National Army, which is allied to an alternative government in the eastern city of Tobruk.
Field Marshal Haftar’s offensive to capture the capital appears to have stalled after five days of fighting, with battles continuing on the southern outskirts.
Forces aligned to Tripoli’s UN-backed Government of National Accord claimed to have recaptured the city’s former international airport, seized by Field Marshal Haftar’s troops two days before.
Almost a week after the assault began, a spokesman for UN Secretary General Antonio Guterres confirmed on Tuesday that a national conference on Libya, planned for April 14 to 16, in Ghadames would not happen “while the bullets are whizzing”.
But UN special envoy for Libya, Ghassan Salame, said he was determined the conference would happen “at the earliest possible opportunity”.
"We cannot allow the historic opportunity it presents to be lost," Mr Salame said. "We also cannot ask Libyans to attend a conference to the backdrop of artillery shelling and air raids."
Tripoli’s central Mitiga Airport remains out of action after it was bombed on Monday by LNA jets, with sources saying those strikes were a reprisal for government jets bombing LNA units at the weekend.
Residents reported the streets in much of the city were calmer than in recent days.
“You can hear the fighting still but it is on the outskirts," a resident said. "Here in the city centre there is nothing."
Tripoli’s health ministry reported that 47 died and 181 were wounded since the start of the offensive.
The International Office of Migration said 2,800 people have been displaced from their homes in Tripoli.
Mr Guterres repeated calls for a ceasefire and political dialogue.
“The secretary general urges the immediate halt of all military operations to de-escalate the situation and prevent all-out conflict,” his spokesman Stephane Dujarric said.
“The secretary general's special representative in Libya stands ready to facilitate that dialogue.”
Mr Salame remains in Tripoli, holding discussions with GNA leaders.
The Ghadames conference had taken many months to arrange and was intended to bring agreement by Libya’s many political groups on the need to hold elections this year.
Meanwhile, there are reports of splits among outside powers, with France, which has in the past supported Field Marshal Haftar, unwilling to condemn his offensive without calling on all sides to halt combat operations.
After a Monday night meeting of EU foreign ministers, policy director Frederica Mogherini said: “I make a very strong appeal to the Libyan leaders, and in particular to Haftar, to stop military activities at this moment and to return to the negotiating table.”
The GNA carried out an air strike on an LNA position in the suburb of Souq Al Khamis on Tuesday but no details of casualties were released.
The UN High Commissioner for Refugees moved more than 150 refugees from a detention centre at Ain Zara in southern Tripoli to areas away from the battlefront.
The fighting has also had an effect on markets, with oil moving to a five-month high of $71 a barrel on fears that the battle may cut Libya’s output.
The ISIS attack appears to be confirmation that the group remains strong in Libya despite operations to eradicate it.
It took control of the coastal town of Sirte in 2015, but the following year it was defeated by Libyan forces backed by US air strikes.
It has since staged periodic attacks in the central desert and in Tripoli.