According to Wink, Umayyad interest in the region was galvanized by the operation of the "Meds" (a tribe of Scythians living in Sindh) and others. The Meds had engaged in piracy on Sassanid shipping in the past, from the mouth of the Tigris to the Sri Lankan coast, in their "bawarij" and now were able to prey on Arab shipping from their bases at Kutch, Debal and Kathiawar. At the time, Sindh was the wild frontier region of al-Hind, inhabited mostly by semi-nomadic tribes whose activities disturbed much of the Western Indian Ocean. Muslim sources insist that it was these persistent activities along increasingly important Indian trade routes by Debal pirates and others which forced the Arabs to subjugate the area, in order to control the seaports and maritime routes of which Sindh was the nucleus, as well as, the overland passage. During Hajjaj's governorship, the "Meds" of Debal in one of their raids had kidnapped Muslim women travelling from Sri Lanka to Arabia, thus providing grounds to the rising power of the Umayyad Caliphate that enabled them to gain a foothold in the Makran, Balochistan and Sindh regions.