The air strikes came as fresh fighting flared Saturday south of Tripoli between the pro-government forces and Haftar's troops despite calls from the global community to halt the military offensive.
The sides have been in an uneasy truce since shortly after Gaddafi's downfall but the country now risks falling into civil war.
Late Friday, the UN Security Council called on Hifter to pull back his forces, warning that further advances would jeopardise any hopes for stability in Libya.
Almost 150 of his soldiers and dozens of vehicles were captured by pro-government forces on Friday as they tried to join the offensive towards Tripoli.
LNA forces briefly took over the ruins of a destroyed airport but were driven out by fighters from the capital, government interior minister Fathi Bachagha told Libya's Al-Ahrar television station.
Pro-government forces from the coastal town of Zawiya battled them, retook the base and captured more than 100 of Haftar's men.
Gen Haftar began his offensive four days ago and fighting on the outskirts of the capital has led some worldwide groups to react to the deteriorating security situation.
"We are agreed that we must use all the possibilities at our disposal to exert pressure on those responsible in Libya especially General Haftar, so that we avoid any further military escalation".
Libya has struggled since the 2011 overthrow of Muammar Gaddafi which left dozens of militia to fill the void and ally with either the GNA or the rival administration in the east backed by Haftar.More news: Smollett refuses to reimburse Chicago for investigation, city set to sue
Anti-government forces led by Haftar earlier said they had been targeted by an air strike about 50 kilometres south of Tripoli.
Haftar's troops have moved into the southern outskirts of Tripoli in a risky thrust against the UN-backed government that has caused alarm among Western capitals.
Rebel forces are advancing on Tripoli in a multi-pronged attack from the south and west of the city, although they have reportedly been slowed by pro-government fighters.
After meeting Friday with Hifter in the eastern Libyan city of Benghazi, Guterres said in a tweet that he was leaving Libya "with a heavy heart and deeply concerned".
UN Secretary General Antonio Guterres urged "calm and restraint" as Haftar forces launched their push for control of the capital.
Analysts say the advance by Haftar's forces comes at a key moment as the United Nations bids to get elections back on track after an abortive effort previous year.
The UN-backed prime minister has accused him of attempting a coup and says rebels will be met with force.
A group of allied militias called the Joint Tripoli Protection Force based in the area around the Libyan capital announced they would also deploy to repel Hifter's offensive.
Gen Haftar has received backing from Egypt and the UAE, who see him as tough on Islamists.