The army, which controls most parts of Eastern Libya, also said Haftar ordered Werfalli’s investigation.
“We inform you that the defendant in your judicial case, Mahmoud al-Werfalli, is under investigation for the cases against him by the general military prosecutor and is now under arrest,” the LNA said in a statement.
ICC issued an arrest warrant for the head of Saiqa Special Forces aligned with the LNA for his involvement in the execution of about 33 bound captives in cold blood, in Benghazi, during the capture of the city last month after nearly three years of combat.
Several videos emerged showing Werfalli participating directly and indirectly in the execution of Islamic State group (IS) suspects.
The LNA indicated that Werfalli was arrested several weeks ago. The army also said it would cooperate with the Hague-based court.
“We announce our readiness to cooperate with you in informing you of the result and course of the judicial case,” the LNA said.
It is unclear whether the LNA will be poised to hand over its commander after the army leadership chided the UN Human Rights Commission over its calling for Werfalli’s suspension last month.
“As for the unverified video,” it said, “we had previously announced that an investigative commission had been formed. Its decision will be publicly announced when the case is closed. Until then, we consider all the charges against our soldiers to be of no value and that they are innocent of those charges until the commission declares otherwise.”