Warplanes affiliated with East Libya-based forces launched an airstrike in the city of Zawiya, west of Tripoli, on Sunday, according to a local military source.
The attack targeted a blacksmith workshop east of the city, the source said on condition of anonymity due to restrictions on speaking to the media.
No casualties were reported.
Eastern Libyan commander Khalifa Haftar launched a military campaign in April to capture Tripoli from the UN-recognized Government of National Accord (GNA).
Libya has remained beset by turmoil since 2011, when long-time leader Muammar Gaddafi was ousted and killed in a bloody NATO-backed uprising after four decades in power.
The oil-rich country has since seen the emergence of two rival seats of power: one in eastern Libya, with which Haftar is affiliated, and the Tripoli-based GNA, which enjoys UN recognition.