A group led by a renegade former general claimed responsibility for an air raid on a military base in western Libya held by rival fighters.
General Saqr Jarrushi, a close aide of general Khalifa Haftar, insisted on Monday that their forces carried out the air strike in Gharyan.
State news agency LANA said 15 people were lightly wounded as the raid hit a munitions depot in the town of Gharyan, 120 kilometres southwest of the capital.
The armed groups in Gharyan form part of Fajr Libya (Libya Dawn), an alliance including Islamists that was targeted by unidentified warplanes near Tripoli airport last month.
Washington said at the time that the United Arab Emirates and Egypt were behind the raids, although Haftar's forces also claimed that attack.
Haftar launched an assault against rival groups in the eastern city of Benghazi on May 16.
Fajr Libya rejects the legitimacy of the elected parliament because it allegedly supported the air raids against its fighters at Tripoli airport.
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The government, in turn, has accused Sudan and Qatar of supplying weapons to its opponents.
Parliament and the internationally recognised government relocated in August to Tobruk, 1,500 kilometres east of Tripoli, as rival factions battled for control of the capital.
Meanwhile, Qatar denied accusation by Libyan Prime Minister Abdullah al-Thinni that it sent three military aircraft loaded with weapons to a Tripoli airport controlled by an armed opposition group.
In a statement to Qatar News Agency, Mohammed bin Abdullah al-Rumaihi, Qatar's deputy foreign minister, described the allegation as misleading and unfounded.
"The policy of the State of Qatar is based on clear and consistent foundations: mutual respect and non-interference in the internal affairs of other countries," said the statement.