East Libyan forces said they lost two helicopters in a crash during a military operation on Sunday, after days of fighting with a formerly allied rebel group from Chad.
The Libyan National Army (LNA) of eastern-based commander Khalifa Haftar has been engaged since last week in battles with the Front for Change and Concord in Chad (FACT) in the south of Libya near the Chadian border.
LNA special forces said in a statement that the two helicopters had collided and crashed during a military operation south of Benina airbase, but did not say whether they were involved in the fighting.
FACT had been based in Libya and fought alongside the LNA during Libya's civil war, receiving heavy arms from Haftar, researchers say.
In April, FACT advanced into northern Chad, battling the army there. Chadian authorities said president Idriss Deby, who had ruled for 30 years, was killed in the clashes. His son has taken over as transitional president.
Major fighting in Libya's civil war has been paused since the LNA offensive ended last year and both sides have accepted a ceasefire, an interim unity government and the idea of elections, although mercenaries remain dug in on both sides.
(Reporting by Reuters Libya newsroom, writing by Angus McDowall, editing by Alexander Smith)
