The government attributed the release to procedural reasons. But critics say it is because Italy depends on Libya to stem the flow of migrants from Africa.

Italy's interior minister said on Thursday a Libyan man detained under an international war crimes arrest warrant and then unexpectedly released had been swiftly repatriated because of his "social dangerousness".

Italian media reports and a Libyan official say police in Turin have arrested a Libyan warlord wanted by the International Criminal Court for alleged war crimes.