All roads leading to the predominantly Sunni town of Qara Tappah, about 120km (75 miles) north-east of Baghdad, were blocked by armed tribesmen, AP news agency reported.
For centuries the oasis had contact with only the few caravan traders that passed along this way via Qara, Qattara and Kerdassa (near Cairo), and the occasional determined pilgrim seeking the famous Oracle of Amun.