Two Sudanese health ministry workers helping to vaccinate children in the Darfur region have been killed, the United Nations said on Saturday, condemning the incident.

The victims, a vaccinator and a driver, were part of a team inoculating vulnerable children against measles in West Darfur state, Ali Al-Za'tari, the U.N.'s chief in Sudan, said in a statement.

Renewed war is increasingly likely in Eastern Sudan, seven years after a peace agreement promised to address complaints of economic and political neglect, a report warned on Tuesday.

"Unless the East's marginalization is adequately addressed, renewed war is a growing possibility," said the Brussels-based International Crisis Group (ICG).

Attackers killed a Rwandan peacekeeper in an ambush on a U.N. convoy in conflict-stricken Darfur on Sunday, the United Nations said.

At least 12 U.N.-African Union peacekeepers have been killed in the troubled Sudanese region in the past five months.

Sudan's President Omar al-Bashir on Saturday called for a battle against inflation as part of efforts to reform the country's indebted, cash-starved and sanctions-hit economy.

"We must fight high market prices which affect the economy and the people," he said in a speech opening a two-day forum of economic experts, politicians and others seeking solutions for the troubled economy.

Sudanese rebels have fired mortar bombs into the capital of South Kordofan state where they rose up against the government two years ago, the insurgents said on Wednesday.

The shelling of Kadugli was in retaliation for an air strike last Sunday that killed two children, Arnu Ngutulu Lodi, spokesman for the Sudan People's Liberation Army-North (SPLA-N), said.

Sudanese rebels on Monday said they had withdrawn from a railway town they briefly occupied before the government launched air strikes.

The Justice and Equality Movement (JEM) early on Sunday entered Abu Zabad, a small community near South Kordofan, a state where rebels have been fighting for two years.

Sudanese rebels on Sunday said they have struck a village near the South Kordofan border, where a resident confirmed fighting was underway.

The Justice and Equality Movement (JEM) said it "took control" of Abu Zabad, in North Kordofan state a few kilometers (miles) from South Kordofan, where rebels have been fighting for two years.

Heavy fighting in a border region of Sudan's Darfur has killed 100 people, state radio reported on Saturday, while another source said Chadian soldiers were among the recent dead.

"The number of casualties has grown to 100" after battles between the Misseriya and Salamat tribes, Radio Omdurman said in a brief bulletin sent by SMS.

Chadian troops in a joint force with Sudan have been killed battling tribal fighters in the troubled Darfur region, a humanitarian source said on Saturday.

The source did not know how many Chadians died in Thursday's fighting with Salamat tribesman around Umm Dukhun, a town on the border with Chad in southwestern Darfur.

Sudanese President Omar al-Bashir hinted on Saturday at an imminent and wide-ranging government shakeup, after the most serious split in years within his ruling party.

"We will soon make changes in the executive and legislative bodies at the federal and state levels," he told his National Congress Party (NCP) shura council.