The United States called Wednesday for an immediate deployment of African troops to safeguard a fragile peace deal reached last week by warring sides in South Sudan.

The ceasefire agreement, signed last week in Addis Ababa, was the fruit of weeks of mounting international pressure and shuttle diplomacy.

Western embassies in Sudan expressed "deep concern" on Tuesday over the case of a woman who activists say risks a death sentence for apostasy.

Meriam Yahia Ibrahim Ishag, who says she is Christian, was convicted last Sunday in the Khartoum-area district of Haj Yousef.

Evidence suggests Iran has played a key role in supporting war-torn Sudan's weapons production and that Tehran has also been Khartoum’s second-biggest supplier of arms, a study said Monday.

Some of those imported arms, along with others from China, have reached rebel groups in Sudan as well as South Sudan, said the Small Arms Survey report based on more than two years of investigation.

Concern mounted on Sunday over accusations that Sudan's air force dropped bombs near a church-run hospital in war-torn South Kordofan.

The European Union delegation to Khartoum said in a statement that it "noted with concern" reports of the bombing, stressing that hospitals are protected civilian facilities under international law.

A ceasefire between South Sudan's government and rebels was due to come into effect Saturday following a deal to end a brutal five-month war that has pushed the country to the brink of genocide and famine.

President Salva Kiir and rebel leader Riek Machar, a former vice president, met in the Ethiopian capital on Friday, shook hands and prayed together, and agreed to order a halt to fighting within 24 hours. Army and aid sources said frontlines appeared to be quiet.

Khartoum on Saturday welcomed a peace deal reached to end five months of war between the government and rebels in neighboring South Sudan.

The foreign ministry affirmed Sudan's "welcome and support" for the agreement between the South's President Salva Kiir and rebel leader Riek Machar, the official SUNA news agency said.

The United States and Canada said Thursday they were "appalled" by an air raid which Sudanese forces reportedly carried out near a church-run hospital in war-torn South Kordofan.

"We strongly condemn any targeting of civilians, and are appalled by this attack on those providing essential medical care or humanitarian assistance to people in need," embassies of the two North American nations said in a joint statement.

Gunmen who attacked peacekeepers in Sudan's Darfur were forced to retreat after a firefight, said Thursday the UNAMID mission which has come under calls to be more aggressive.

The incident happened on Sunday when a patrol of the African Union-United Nations Mission in Darfur came under fire from unidentified gunmen near Sindy, about halfway between the North Darfur towns of Malha and Mellit.

Two Iranian warships docked in Sudan on Monday, Khartoum's military said, emphasizing what analysts say are poor relations between Islamist Sudan and its Arab neighbors.

Sudan's army spokesman Sawarmi Khaled Saad said the warships, one of them a navy supply ship, had arrived in Port Sudan.

Police fired tear gas in the Sudanese capital on Monday when clashes between pro-government university students and their opponents spilled onto a downtown street, witnesses said.

"Both sides had steel bars, stones and chains and some of them clashed outside campus," said one student witness at the University of Khartoum.