evidence: Sudan has warned against an "illegal" offering of oil and gas exploration blocks by Egypt in the Red Sea area of Halayeb, a territory claimed by both countries. Egypt's occupation of the Halayeb Triangle, which lies in a mineral-rich border region of the Red Sea, has been a bone of contention for years between Cairo and Khartoum despite an overall improvement in ties since an October summit. [...] The Halayeb triangle, which is controlled by Egypt, has been claimed by Sudan since the 1950s.