The Government of National Accord (GNA) did not say how many people had been killed and injured in the strikes, but military forces aligned with the GNA said 14 people had died.
The strikes mark the latest escalation in an air campaign as the eastern-based Libyan National Army (LNA) presses its military offensive on the outskirts of Tripoli and seeks to retain control over desert areas in the south.
The strikes hit Al-Sawani, south-west of central Tripoli on Sunday, and Umm al-Aranib town, about 765km (475 miles) away, late last week.
Emergency workers confirmed that three children had been killed and a fourth child injured in the strike in Al-Sawani, which they said damaged some houses and vehicles.
In Umm al-Aranib locals protested against the strikes on Monday, burning tires in the street and closing some schools and roads, residents said.
There was no immediate comment from the LNA, which since early April has been waging a military campaign to try to take control of Tripoli.
After the offensive quickly stalled, both sides became increasingly dependent on air strikes carried out with foreign support by fighter jets and drones.
The United Nations Libya mission, UNSMIL, said in a statement sent to Reuters that it was "following with great concern the intensification of airstrikes in civilian areas in the past few days."
"UNSMIL stresses that indiscriminate attacks against civilians and civilian infrastructure constitute a grave violation to international humanitarian and human rights," it said.
Umm al-Aranib is about 275km directly east of El Feel oilfield, where GNA-aligned forces briefly took control last week before being beaten back by air strikes.
Libya has been divided since 2014 between shifting rival political and military factions based in Tripoli and the east.