Russian fighter aircraft recently delivered to Libya in support of Khalifa Hifter's campaign against the Tripoli-based government are now being put to use.

Imagery released by US Africa Command on Thursday shows an Su-24 attack aircraft using the runway at al-Jufrah air base in central Libya. AFRICOM also lent credibility to recent photographs purportedly showing a MiG-29 flying near the northern coastal city of Sirte, where the Tripoli-based government has focused its counteroffensive.

A spokesperson said AFRICOM does not yet know who the pilots are, raising concern that Wagner mercenaries or Libyan pilots without proper training may be preparing to use the aircraft in combat against the United Nations-backed Government of National Accord.

“The belief is the Russian pilots are conducting basic flying, working on proficiency and gathering situational awareness,” US Air Force Col. Christopher Karns, head of AFRICOM’s public affairs office, told Al-Monitor. “If it is Russian pilots, this would represent an escalation,” Karns said, adding that AFRICOM has no evidence the aircraft have yet carried out strikes.