JUBA, South Sudan — The northern Sudanese air force bombed a key airstrip Tuesday in the rugged Nuba Mountains in what aid groups said might be an effort to cut off humanitarian assistance to the region a month before southern Sudan is scheduled to become an independent nation.
The bombing of the Kauda airstrip could leave hundreds of thousands of Nuba tribesmen, most of whom sided with the south during Sudan's long civil war, without an aid supply line. When Sudan splits into two countries on July 9, the Nuba will fall on the northern side of the border.
Fighting has raged for 10 days between government forces and former rebel fighters, and reports from the region indicate that the predominantly Arab northern forces have targeted Nuba civilians, who are minority Africans.
"The reports being received from various quarters point to a deliberate process of ethnic cleansing; unfolding before us is yet another human tragedy in Sudan," said a statement Saturday from the All Africa Conference of Churches.
It's the second time in the last month that northern Sudanese forces have been accused of ethnic cleansing against ethnic Africans near the north-south border. On May 21, the northern military and aligned militias stormed into Abyei — a disputed border district held by the south — and pushed out more than 100,000 southerners. An internal U.N. human rights report May 29 described the northern actions, which included burning and looting of homes, as "tantamount to ethnic cleansing."
This time, however, civilians caught in the fighting in and around Sudan's Nuba Mountains — within the northern border state of South Kordofan — have nowhere to flee, and are coming under heavy aerial attacks.
Death tolls are impossible to determine. Many humanitarian agencies have evacuated their staffs and those still there have limited access on the ground.
The only major international contingent in South Kordofan — a United Nations peacekeeping force — is mostly hunkered down within its base in the state capital, Kadugli, trying to protect and feed 6,000 Sudanese who've fled to the vicinity of the base for safety.
Fighting in Kadugli also intensified Tuesday. Northern aircraft bombed the city and the surrounding area for much of the day, while Nuba fighters aligned with the south claimed to have seized a significant portion of the city, including some northern military barracks. Other reports suggest that a sizable contingent of northern forces mutinied. None of the information was verifiable.
Days of heavy aerial bombardment over civilian areas also hasn't slowed.
"We are extremely concerned about this bombing campaign, which is causing the huge suffering of civilian populations and endangering humanitarian assistance," said Kouider Zerrouk, acting spokesman for the United Nations mission in Sudan.
In the early 1990s, during Sudan's civil war, the Nuba came under systematic attack by the government. Arab militias razed villages and as many as 500,000 Nuba were estimated to have died, more people than are thought to have died in the ethnic slaughter in Darfur since 2003.
Aid workers and others in the area say they think that Nuba civilians are being targeted in the current fighting because of their ethnicity. In some cases, soldiers are going door-to-door, and the bombing campaign seems to be targeting civilian centers.
Outside humanitarian aid groups have effectively been shut out of the area. The northern government has shut down the Kadugli airport, and U.N. stockpiles are dwindling.
Complete isolation might have been cemented by the Kauda airstrip bombing Tuesday. That dirt landing strip served as a backdoor route for humanitarian assistance from East Africa during the war, and has remained active.
Kauda is also the traditional base of the Nuba rebel forces, and it's still the base of many of the humanitarian organizations that operate in the surrounding area.
Meanwhile, northern soldiers and militiamen were reported ominously circling the U.N. compound in Kadugli and the displaced families outside.
"It is a very, very worrying situation," said a fearful U.N. Sudanese staff member, who asked not to be identified, speaking Tuesday from within the U.N. Kadugli compound. "Our lives and the lives around us are at a lot of risk."
The U.N. employee said the northern forces were targeting Nuba in the camp outside and even among U.N. employees themselves. He said that since Sunday, two Nuba U.N.-associated colleagues had been assassinated just outside the U.N. gate.
The U.N.'s Zerrouk said he couldn't confirm the killings. "We take these allegations seriously, and we'll definitely investigate the matter," he said Tuesday.
(Boswell is a McClatchy special correspondent. His reporting from Sudan is supported in part by Humanity United, a California-based foundation that focuses on human rights issues).
MORE FROM MCCLATCHY
For more international news visit McClatchy's World page.