Forces loyal to eastern Libyan commander Khalifa Haftar said they destroyed a Turkish drone parked at Tripoli's only working airport on Sunday, halting civilian flights as tensions between Ankara and the eastern administration mounted.
Haftar's forces said they hit the drone in an air strike on Mitiga airport, part of a series of measures meant to punish Turkey for its support of the rival, internationally recognised Libyan government in Tripoli.
They also said they had arrested two Turks in the northeastern oil town of Ajdabiya.
Turkey's foreign minister earlier accused Haftar's supporters of arresting six of its citizens and warned that the eastern forces would become a "legitimate target" if the Turks were not released immediately.
Haftar's Libyan National Force (LNA) launched a campaign on April 4 to try seize the Libyan capital - but has been pushed back by the Tripoli government's forces which are supported by Turkey.
Haftar and his backers say they are trying to free Tripoli from militias that they accuse of destabilising Libya since the fall of Muammar Gaddafi in a NATO-backed uprising in 2011.
Haftar's critics including Turkey accuse him of trying to seize power from the legitimate government through force and deepening a conflict between factions based in the east and west of the sprawling North African country.
Haftar's administration cut all ties with Turkey on Friday, banning its flights and ships from eastern Libya.
It upped those measures on Sunday by declaring Turkish firms, imports and even symbols illegal. Ankara has supplied drones and trucks to forces allied to Tripoli's Western-backed prime minister, Fayez al-Serraj, while Haftar's Libyan National Army (LNA) has received support from the United Arab Emirates and Egypt, according to diplomats.
Haftar's offensive has upended United Nations-led plans to stabilise Libya after years of conflict that have left the oil producer divided and caused living standards to plummet.
The conflict risks disrupting oil production, creating a vacuum to be exploited by militants and prompting more migrants to head for Italy by boat.