A recent escalation in military activity in western Upper Nile (Wahdah, or Unity State) could be due to a major government offensive to gain control of oil production areas, according to humanitarian sources.
"An offensive which started around November has been increased in the last few weeks. We have reports that troops have come in from Kassala [in eastern Sudan] and from the Nuba Mountains [in Southern Kordofan, south-central Sudan] following the cease-fire agreement there," aid workers told IRIN on Tuesday.
Following a helicopter gunship attack on a relief centre at the village of Bieh on 20 February, in which at least 24 people were reportedly killed, the US government announced it was suspending peace discussions with Khartoum until a satisfactory explanation was offered.
The incident at Bieh was the second clearly verified air attack on civilian targets in the oil-rich region in February. The village of Nimne, also in western Upper Nile, was bombed by government aircraft on 9 February, killing five civilians, including an employee of the international health organisation Medecins Sans Frontieres (MSF).
Apart from the attacks at Bieh and Nimne, there had been reports of increased government activity in civilian areas, with helicopter gunships reportedly flying low over villages, sources said.
A "massive increase" in attacks originating in Bentiu, the main government garrison town in the area - and capital of western Upper Nile/Unity State - had been observed, with a number of bombing raids by government Antonov aircraft being launched from there, they added.
The government of Sudan, for its part, has expressed concern that the rebel Sudan People's Liberation Movement/Army (SPLM/A), rather than pushing for peace, was "actually intensifying its acts of sabotage and military operations in areas of oil production."
To that end, it said, the rebel movement had "declared Unity State in southern Sudan as a military operations area."
The government stated, in a Foreign Ministry press release, that it was defending the sovereignty of the state and its citizens in the light of "imposed military aggression by the other party to the conflict."
In those circumstances, although it was government policy to ensure that civilians were not targets in areas of conflict, "unforeseen casualties happen to innocent civilians", the statement said.
Khartoum reaffirmed its commitment "to achieve a peaceful and just settlement of the conflict in southern Sudan" and called on the international community to pressure the SPLM/A into halting "the current, unjustified escalation of military operations."
The apparent increase in government-sponsored military actions appeared to be linked to the signing of a merger agreement in January between the two largest rebel groups active in southern Sudan - the Sudan People's Liberation Movement/Army (SPLM/A) and the Sudan People's Defence Forces (SPDF).
At the time of that agreement, the Sudanese government described the merger as a "negative step", saying it could adversely affect the country's peace process.
Prior to the merger, SPLA and SPDF forces had often been in conflict in western Upper Nile, with the SPDF suspected of working with government forces to secure oil production sites against SPLA attack, according to regional analysts.
Hostilities between the two rebel groups in western Upper Nile appeared to have ended in February, however, when the local SPLA commander, Peter Gadet, and his SPDF counterpart, Peter Par, signed a local-level agreement in the village of Koch to implement the merger. This resulted in the government suddenly losing a useful lever with which to control the area, analysts said.
"There has been a change of tactic [by the government] following the SPLA-SPDF agreement. All areas in the region are now perceived to be rebel-held areas," according to humanitarian sources.
"They [the government] have been worried since the SPLM and SPDF merged," SPLM/A spokesman Samson Kwaje told IRIN on Tuesday. "They are the ones that have mounted the offensive."
Some analysts say the merger could have serious implications for the oil industry in Sudan, with several rebel factions regarding attacks on the oil infrastructure in western Upper Nile as a priority. SPLM/A leader John Garang has repeatedly claimed that the oil installations are "legitimate targets" in Sudan's 19-year civil war.
The Swedish oil company Lundin Petroleum AB announced in January the suspension of its operations in oil concession area Block 5a "as a precautionary measure to ensure maximum security for its personnel and operation", as a result of the deterioration of security levels in the area.
The government has held that the attacks on Bieh and Nimne were unfortunate mistakes stemming from its response to rebel attacks. It has also claimed that rebel forces, and not the government, were responsible for targeting civilians.
"The [SPLA-SPDF] alliance has targeted our armed forces, which have been performing their duty of protecting the oil," the Sudanese army said in a statement reported on Republic of Sudan Radio on 21 February. The SPLA-SPDF alliance had also been responsible for "targeting civilians working in the area of development and growth of Unity State", it added.
According to analysts, however, government forces could be aiming to secure the main road running from the town of Bentiu, a government-held oil producing centre, south to the government garrison town of Leer (Ler, 8.18 N 30.08 E), in order to facilitate access to oil concession block 5a.
SPLA Commander Peter Gadet's forces had reportedly repulsed several attempts by the government to advance out of Bentiu down the "oil road", according to humanitarian sources. "There is an ever-increasing offensive to open the road to Leer. We have reports of lots of tanks and other armoured vehicles moving in the area," they said.
An escalation of fighting would exacerbate the problems faced by thousands of displaced people in western Upper Nile, informed relief workers told IRIN this week. As many as 50,000 civilians could be expected to flee south from Bieh, Leer, Koch, Duar, Nhial Diu and Mankien Payam districts, they said.
The Sudanese government on 23 February claimed to have captured the airstrip situated at Nhial Diu, some 40 km southwest of Bentiu.
"After continuous fierce fighting in Wahdah (Unity) State, the army and militia were able to take control of the main base of the rebels, and occupied the airport at Nhial Diu," AFP quoted army spokesman General Muhammad Bashir Sulayman as saying.
Samson Kwaje told IRIN on Monday that he could neither confirm nor deny the government's claims.
Many civilians had sought sanctuary at Nhial Diu following previous outbreaks of fighting in western Upper Nile, humanitarian sources reported. As a result of renewed government offensives, they were now being pushed further afield; there was now a danger they could be forced into Bahr al-Ghazal, possibly putting pressure on Dinka communities there at a time when food security was "precarious" following a modest harvest.
The US government, through its peace envoy, John Danforth, has been attempting to build confidence in the Sudanese peace process with four specific measures, including a proposal to deploy independent monitors to help protect civilians from attack.
According to Danforth, however, the Bieh helicopter gunship attack took place despite indications by the Sudanese government last week that it would accept an international mechanism to verify the protection of civilians in the Sudanese civil war.
Danforth is expected to submit a report to US President George W Bush within the next few weeks on the feasibility of Washington taking an active role in efforts to end Sudan's 19-year civil war.
However, the Sudanese army statement of 21 February appeared to offer little hope for an end to fighting in western Upper Nile.
"We would like to warn civilians and other organisations to stay away from the region of the current military operations to preserve their souls and property," it said.