Drone strikes early on Friday hit an airbase in Libya's east used by mercenaries of the Russian paramilitary group Wagner, without causing any casualties, a military official told AFP.
The official, speaking on condition of anonymity, said the origin of the overnight strikes on the Al-Kharruba airbase, about 150 kilometres (90 miles) southwest of Benghazi, was "unknown".
The base that was hit is "where members of the Wagner group are located", the official said, adding there were "no victims".
Libya has been torn by more than a decade of stop-start conflict since a 2011 revolt toppled dictator Muammar Gaddafi, which has also drawn in multiple foreign powers.
The North African country remains split between a nominally interim government in Tripoli in the west, and another in the east backed by military strongman Khalifa Haftar.
Alongside fighters from Chad, Sudan, Niger and Syria recruited as mercenaries, the Wagner group has come to Haftar's help including in his past failed attempt to take the capital.
Wagner mercenaries remain active in oil-rich eastern Libya as well as the country's south, though some had left to fight in Mali and Ukraine, supporting the Russian army's invasion.