Forces loyal to Libyan commander Khalifa Hifter said their campaign against an armed coalition of local fighters and Islamists in the eastern city of Derna has reached its final stages after several days of heavy fighting.

Brigades from Hifter's Libyan National Army (LNA) launched a ground offensive to take Derna last month after encircling the city — the last in eastern Libya to elude their control — for around two years.

The fighting risks undermining U.N.-led efforts to reunify Libya and hold elections after years of turmoil that have provided a safe haven to militants and people smugglers, and crippled Libya's oil-dependent economy.