A leading Sudanese opposition party on Monday called for a transitional government to help resolve multiple crises in the impoverished, war-ravaged nation.

Reform Now, in a joint statement with several smaller political parties, said the transitional administration should put into effect the outcome of a national political dialogue called by President Omar al-Bashir in response to Sudan's problems.

Secretary of State John Kerry vowed Tuesday to defend democratic values and human rights as he met civil society groups ahead of a major U.S.-Africa summit.

On the eve of a summit attended by several leaders with checkered records, Kerry told activists gathered in Washington that the United States hoped to help Africa build strong institutions rather than to bolster individual leaders.

The attendance of nearly every African nation at an unprecedented summit in Washington on Monday is "abnormal" as long as Sudan is excluded, Khartoum says.

Sudan's President Omar al-Bashir, who is wanted for alleged war crimes, is one of only four leaders not invited by U.S. President Barack Obama for the three-day meeting focused on building economic ties between the two continents.

When the skies again unleashed their fury over Khartoum before dawn on Sunday, there was little of Kamel Hussein's home left to be destroyed.

More than 3,000 homes have been destroyed by floods that hit almost half of Sudan's states over Ramadan and the Eid Al-Fitr holidays, official media said on Saturday.

"Twenty-two districts in eight states were affected by flooding and heavy rain," the SUNA news agency reported, citing the federal health ministry.

Amid civil war and famine warnings, South Sudan's tough security forces have cracked down on journalists, suffocating debate on how to end the fighting, rights groups warned Friday.

South Sudan's feared National Security Service (NSS) should "stop seizing and shutting down newspapers as well as harassing, intimidating, and unlawfully detaining journalists," Amnesty International and Human Rights Watch said in a joint report.

A Sudanese Christian woman -- sentenced to death for renouncing Islam but acquitted after international pressure on Khartoum -- has arrived in the United States with her family.

Meriam Ibrahim Tehya Ishag flew first into the east coast city of Philadelphia Thursday, where she was welcomed by the mayor as a "world freedom fighter," media reports said.

A Sudanese Christian woman who was sentenced to death for renouncing Islam then acquitted after international pressure on Khartoum, on Thursday left Italy for the United States with her family.

Meriam Ibrahim Tehya Ishag, who met Pope Francis during her eight-day stopover in Italy, took an American Airlines flight for Philadelphia.

Crude camps housing South Sudanese have been flooded by heavy rains that inundated the Sudanese capital over the Eid al-Fitr holiday, a southern diplomat said on Wednesday.

Rain and high winds lashed Khartoum overnight Tuesday, soaking homes and streets for the second time since Friday at the start of the rainy season.

A Sudanese Christian woman whose death sentence for renouncing Islam sparked a global outcry that eventually led to an acquittal, met Pope Francis after arriving in Italy en route to the United States.

Meriam Yahia Ibrahim Ishag and her family were received by the Argentine pontiff at his home for a 30-minute meeting Thursday in which he thanked her for her "courageous testament of faith" and her "tenacity", the Vatican said in a statement.