(REUTERS) - Fighters from the United Nations-recognised Government of National Accord (GNA) engaged in an escalating battle at the frontlines last Saturday (April 13) in the southern town of Ain Sara, as the conflict over the Libyan capital Tripoli against Khalifa Haftar's Libyan National Army (LNA) continues.

GNA fighters were seen chanting "God is Great" as they charged with machine guns, opening fire in response to LNA offensives.

By last Friday, the latest battle killed 75 people, mainly fighters but including 17 civilians, and wounded another 323, according to UN tallies. Some 13,625 people have been forced out of their homes.

As well as the humanitarian cost, the conflict threatens to disrupt oil supplies, boost migration to Europe, scupper a UN peace plan, and allow Islamist militants to exploit the chaos.

Haftar, 75, a former general in dictator Muammar Gaddafi's army who later joined the revolt against him, moved his troops out of their eastern stronghold to take the oil-rich desert south earlier this year, before sweeping up to Tripoli at the start of April.