TRIPOLI (Reuters) - Heavy fighting raged overnight in the battle for the Libyan capital Tripoli, with neither faction able to secure gains on the frontlines as an offensive by eastern commander Khalifa Haftar entered its fifth week.
Haftar's Libyan National Army (LNA), which is allied to a parallel administration based in Benghazi, has in the past week brought up more troops and heavy guns to the frontline.
But it has been unable to breach the defences in the city's southern suburbs of forces loyal to the internationally recognised government in Tripoli.
Libya has been in a state of chaos since Muammar Gaddafi was toppled in 2011 after 40 years in power by insurgents backed by NATO air power.
The battle for Tripoli has all but wrecked U.N.-backed efforts for a peace deal between the rival factions, and has disrupted the oil industry of a country that is one of Africa's largest producers.
ON THE FRONTLINE
Heavy fighting raged from Thursday afternoon until early morning Friday in the area of the former international airport but the frontline has changed little, residents said.
The LNA moved up on one part of the front earlier this week but was repelled by the Tripoli forces, who had built barriers, including shipping containers, on southern roads where tanks and artillery guns are in position.
The Tripoli forces regained some ground but analysts say the threat of the LNA will persist as long as it keep its forward base in Gharyan, about 80 km (50 miles) south of Tripoli.
The town is difficult to take because it lies in mountains that rise from the coastal plain on which Tripoli sits.
The LNA, whose principle supporters include Egypt and the United Arab Emirates, has sent troops and material to Gharayn by road from Haftar's power base in Benghazi, the main eastern city, or via the central air base in Jufrah, military sources say.
A Tripoli government spokesman said his administration was talking to its ally Turkey to obtain military and civilian help - "anything that is needed to stop the assault".
In Geneva, the United Nations said that despite the latest clashes, no air strikes or artillery barrages had hit civilians or residential areas. Since the offensive began, 102 civilian casualties had been counted, 23 of them killed, it said.
More than 48,500 people in Tripoli had fled their homes for safer areas, it said, including 6,000 registered in the past 48 hours.
Others remain trapped in conflict zones, where food is running short and the wounded and sick are in need of medical help.
European countries are concerned the fighting could provoke a new flight of refugees and migrants from Libya and elsewhere in Africa across the Mediterranean. Trafficking gangs have used Libya as a hub for their operations.
The latest flare-up also threatens to leave a power vacuum that Islamist militants could exploit.
French Foreign Minister Jean-Yves Le Drian meanwhile dismissed accusations by the Tripoli government that Paris was supporting Haftar in his current offensive. France's interest was to fight terrorism, he said.
"This is our objective in the region," Le Drian told Le Figaro newspaper.
France also supported the Tripoli government of Prime Minister Fayez al-Serraj, Le Drian said in his first public comments since the offensive began.
The United Nations' Libya envoy has suggested Paris and others were too close to Haftar, and Tripoli has accused France of playing both sides.
France has backed Haftar in his efforts to fight Islamist militants in Libya in the past, including with military support.
Le Drian said he had no inkling that Haftar would launch the offensive on Tripoli despite visiting Benghazi and Tripoli a few days earlier. But he did not disavow Haftar and laid the blame on both sides.
"I realised, contrary to our expectations, that the situation was blocked. Serraj like Haftar was hesitating to cross the hurdle to conclude a (political deal)," he said.
Last month the European Union urged the LNA forces to halt their assault on Tripoli, but its statement was held up by disagreement between France and Italy.
The final version did not mention Haftar directly by name, shifted away from blaming his offensive exclusively for the escalation, and referred to the presence of Islamist militants among the anti-Haftar forces.
(Reporting by Ulf Laessing in Tripoli, additional reporting by John Irish in Paris, Editing by Angus MacSwan)