Benghazi - The forces of Libyan military strongman Khalifa Haftar said on Friday they had detained a senior commander two weeks before the International Criminal Court issued a warrant for his arrest over unlawful killings in the flashpoint city of Benghazi."We hereby inform you that the defendant... has been arrested and investigated by the military prosecutor on those charges" since August 2, as ordered by Haftar, said the general command of his armed forces.The International Criminal Court (ICC) announced on Tuesday that it had issued a war crimes arrest warrant for Mahmoud Mustafa Busayf al-Werfalli, "allegedly responsible for murder as a war crime in the context of the non-international armed conflict in Libya".Werfalli commanded a unit battling alongside Haftar's forces in Libya's second largest city, from which jihadists were finally ousted in July following a three-year military campaign.He is accused of involvement in at least seven incidents in 2016 and 2017 in which he allegedly personally shot or ordered the execution of either civilians or injured fighters, The Hague-based court said.Haftar's general command, in a statement received by AFP, stressed its "respect for international conventions, international human law and the teachings of Islamic Sharia laws".It had "stated on many occasions and in official statements" for members of Haftar's forces "to respect these rules" and to "hand over terrorists to the competent authorities"."The ICC should rest assured that investigation procedures ensuring justice are ongoing under Libyan military law and the defendant has been suspended and detained," it said."We are ready to cooperate with ICC by sharing the trial proceedings."The ICC announcement on Werfalli came with the court still in a legal tug-of-war with Libyan authorities to transfer Seif al-Islam, the son of the country's ousted leader Moammar Gaddafi, to The Hague.The ICC and Libyan authorities have been in dispute over who has the right to judge him.Seif faces crimes against humanity charges for his role in the Gaddafi regime's brutal attempts to put down the 2011 uprising which eventually toppled and killed his father.Seif's exact whereabouts are unknown, following a claim in June by militia that it had freed him.The ICC, set up to investigate and prosecute the world's worst crimes, opened its Libya probe in March 2011 to investigate atrocities committed during the uprising that erupted a month earlier.The ICC aims to complement but not replace national courts and only prosecutes cases when countries are "unwilling or unable to do so genuinely".