The Satellite Sentinel Project said the images show heavily camouflaged military equipment and several thousand troops moving south toward the rebel stronghold of Kurmuk in Blue Nile state. The group said the force appears to be equipped with tanks, artillery and infantry fighting vehicles.
"Since May, the government of Sudan has used indiscriminate and disproportionate force, including campaigns to bombard civilians, in the three border areas of Abyei, South Kordofan, and Blue Nile State," said Enough Project Executive Director John C. Bradshaw. "This irrefutable, visual evidence of massive military operations in Blue Nile State provides a human security warning to civilians in Kurmuk and the surrounding area."
South Sudan, a region of black tribesmen, officially broke away from the mostly Arab north Sudan in July. But residents in the three border areas who are aligned tribally and politically with the south have seen military attacks from Sudan, according to human rights groups.Late last month international rights groups accused Sudan's government of killing at least 26 people in indiscriminate aerial bombardments in the Nuba Mountain areas of South Kordofan state.
The rights groups said that Sudanese government restrictions have prevented aid groups from delivering food and other assistance to more than 150,000 people displaced by violence in the contested region.
Sudan's government has said that the contested regions are home to rebels armed by South Sudan and urged the U.N. to take action against South Sudan for violating a 2005 peace deal that ended decades of conflict.
The Satellite Sentinel Project said last month that satellite imagery found two more mass graves in South Kordofan, bringing the total number of graves seen there to eight.