The United Nations acting Libya envoy said on Wednesday that foreign supporters of both sides in the civil war were helping them stockpile weapons in breach of an arms embargo and as coronavirus
"spirals out of control" in the country.
Some 70 resupply flights had landed in eastern airports in support of the Libyan National Army (LNA) of Khalifa Haftar since July 8, Stephanie Williams told the UN Security Council.
In the same period, 30 flights and nine cargo ships had carried materiel to western Libya to assist the UN- recognised Government of National Accord (GNA) in Tripoli.
She did not name the countries involved. The LNA is supported by the United Arab Emirates, Russia and Egypt, while the GNA is backed by Turkey.
The conflict has fed into a wider tussle for influence among those countries in the eastern Mediterranean area. Williams warned that any reckless action "risks igniting large-scale confrontation, with the devastating consequences this would entail for the country and the region at large".
Libya's conflict and a blockade on oil exports by eastern forces have worsened living conditions amid a rapid surge in the coronavirus in some parts of the country, with the number of confirmed cases doubling over the past two weeks to 15,156.
"Exponential increases are a worrying trend with community transmission now reported in some of Libya's main cities," Williams said, adding that the true scale of the pandemic in Libya was likely far higher than recorded numbers showed.
"Nearing full collapse after more than nine years of conflict, the health care system is unable to respond," she said.