UNITED NATIONS, Aug. 14 (Xinhua) -- The top UN envoy to Sudan said Thursday that recent violent clashes in the town of Abyei as well as the attack by a rebel group on the city of Omdurman have put the country's 2005 peace agreement to a test, according to a UN press release.

    "Each points up the fragility of the peace process. Each serves as a cautionary reminder of the potential consequences for Sudan and its people should the peace process unravel or derail," Ashraf Qazi, UN chief's special envoy to Sudan told reporters in Khartoum.

    After the May violence, tens of thousands people fled their homes in Abyei, which lies in an oil-rich area close to the boundary between northern and southern Sudan.

    In May, members of the Darfur rebel group, the Justice and Equality Movement (JEM), also launched an attack on Omdurman, near Khartoum.

    Qazi, who also heads the UN Mission in Sudan (UNMIS), said there were also reasons for optimism, noting that the implementation of a recent agreement to settle the conflict over Abyei provided a strong indication of the parties' commitment to peace.

    "I hope that the appointment of a Chief and Deputy Administrator will soon be followed by the full establishment of the interim administration and move us all closer to the day when those displaced by the May fighting can return in safety and dignity to resume their lives in a secure environment," he said.