Italian Prime Minister Giorgia Meloni and her government are under fire due to the release of a Libyan warlord on a technicality, after he was arrested on a warrant from the International Criminal Court (ICC) accusing him of war crimes and crimes against humanity.

The Hague-based court, for its part, issued a more diplomatic response, but its anger appeared evident.

In a statement, the ICC reminded Italy that it is obliged to "cooperate fully" with its prosecutions and said it was still awaiting information about what exactly Rome had done.

This came after the Italian government released and sent back home Ossama Anijem, also known as Ossama al-Masri, who heads the Tripoli branch of the Reform and Rehabilitation Institution, a notorious network of detention centers run by the government-backed Special Defense Force.

Al-Masri had been arrested Sunday in Turin, where he reportedly had attended the Juventus-AC Milan football match the night before.

The ICC warrant, dated the day before, accused al-Masri of war crimes and crimes against humanity committed in the Mitiga prison in Libya starting in 2015 that are punishable with life in prison.

According to the ICC, al-Masri was accused of murder, torture, rape and sexual violence.

The warrant was transmitted to member states on Saturday, including Italy, the ICC said, adding that the court had also provided real-time information that he had entered Europe.

But Rome's court of appeals ordered al-Masri freed Tuesday, and he was sent back to Libya aboard an aircraft of the Italian secret services because of what the appeals court said was a procedural error in his arrest.

'A stunning blow' to victims

The ruling said Justice Minister Carlo Nordio should have been informed ahead of time, since the Justice Ministry handles all relations with the ICC.

Human rights groups criticized Italy for letting al-Masri go.

"This is a stunning blow to victims, survivors and international justice," said Amnesty International's Esther Major, deputy director of research for Europe, calling it a "missed opportunity to break the cycle of impunity in Libya."

Italy has close ties to the internationally recognized government in Tripoli, on whom it relies to patrol its coasts and prevent waves of migrants from leaving.

A trial in The Hague of al-Masri could bring unwanted attention to Italy's migration policies and its support of the Libyan coast guard, which it has financed to prevent migrants from leaving.

Human rights groups have documented gross abuses in Libyan detention facilities where migrants are kept and have accused Italy of being complicit in their mistreatment.

ftm/jcg (dpa, AP)