ANKARA: Turkey said on Sunday six of its nationals were being held by forces of Libyan strongman Khalifa Haftar after earlier warning Ankara was ready to retaliate against attacks.

Haftar has ordered attacks on Turkish ships and interests after he recently lost ground to the UN-recognised Libyan government which is also backed by Turkey.

`The detention of six of our citizens by illegal militia forces linked to Haftar is an act of thuggery and piracy. We expect our citizens to be immediately released,` the foreign ministry said in a statement.

`Should this not happen, Haftar elements will become legitimate targets,` it added. But the ministry did not giveany details on where the Turks were being held or when they had been taken by the Libyan militia.

A ministry source said there was `no additional information to give at this stage`.

Haftar instructed his self-styled Libyan National Army to target Turkish companies, ban flights and arrest Turkish nationals in Libya, his spokesman said on Friday.

Af ter a Nato-backed uprising that led to death of dictator Muammar Qadhafi in 2011, Libya was propelled into chaos with militias fighting for control of the country. Haftar was a retired general who had taken part in the revolt against Qadhafi but in May 2014, he launched his assault to purge the country of Islamist `terrorists`.-AFP