Libya’s prime minister, Abdullah al-Thinni, has accused Qatar of sending three planes loaded with weaponry to arm Islamist militias, heightening fears the country is becoming a battlefield for a proxy war between rival Gulf states.

“Unfortunately, [the planes] reached [Tripoli’s] Matiga airport,” said Al-Thinni, speaking on Sky News Arabia.

The premier warned that Libya was considering breaking off relations with Qatar if the nation continued to interfere in Libyan politics by continuing to assist the Islamist-led militias, many of which hail from the port city of Misrata.

“We confirm that we have official reports that these war planes carried weapons and ammunition,” he said.

The allegations come after the Misrata militias overran Tripoli International airport on 23 August, defeating rival groups from the mountain town of Zintan and taking control of the capital.

In the weeks before the Misratans seized the airport, they were targeted by air strikes that US officials say were carried out by the UAE with assistance from Egypt.

Since the escalation in violence in Tripoli and Benghazi, Libya’s second city, the elected government has made its base in the eastern city of Tubruk.