TRIPOLI, June 18 (Reuters) - Libyan government officials on Wednesday condemned a U.S. operation to arrest a man suspected of masterminding a deadly raid on the U.S. consulate in Benghazi, describing the detention as an attack on their country's sovereignty. Justice minister Saleh al-Marghani said the suspect Ahmed Abu Khatallah should be returned to Libya and tried there, in the first official reaction from Tripoli. (Reporting by Ulf Laessing and Ahmed Elumami; Editing)