UNITED NATIONS – World leaders yesterday feared political deterioration in Sudan following the death of the war-torn country’s vice president, John Garang. Although crowds rioted yesterday in Khartoum, where protesters blamed the government for the former rebel leader’s death, there were indications that the north-south agreement would survive the most recent setback.

America has dispensed nearly $1 billion in aid to Sudan in 2005, and plans to invest more pending an end to the violence in the Western region of Darfur. Increased political instability, however, could change American and world aid spending. Many in the diplomatic community said yesterday that they hoped Garang’s death in a plane crash yesterday would not end the process that began with the north-south agreement six months ago. Garang, 60, who was sworn in as Sudan’s first vice president three weeks ago, headed the southern-based Sudan People’s Liberation Movement.

Rioting in the Sudanese capital of Khartoum left 36 dead and about 300 injured, the government said, according the Associated Press. The AP reported that it was unclear how many of those killed were protestors and how many were members of security forces.

Garang “was a very large figure in Sudan, you might call him the father, or a father, of the united Sudan,” a former American ambassador to the United Nations, John Danforth, told The New York Sun. “I am one who mourns his death,” Mr. Danforth said, “but if the question is, is that the end of the unified Sudan, the answer is that it’s not the end.”

Perhaps more than any other American, Mr. Danforth, who before assuming his role as U.N. ambassador served as President Bush’s point man in Sudan, is identified as a broker of last year’s pact between the northern based Sudanese government, the SPLM, and other rebels. Those agreements were not made with Garang, but with a movement, Mr. Danforth said, which is why he said they could survive the death of the group’s leader.

Assistant Secretary of State Connie Newman and Secretary Rice’s Sudan representative, Roger Winter, will go to Southern Sudan and Khartoum to “confer with the parties and encourage them to maintain momentum” on the north-south agreement and Darfur, a State Department spokesman, Tom Casey, announced yesterday.

Garang’s body was found Monday. His helicopter crashed earlier, probably late Saturday or early Sunday, into a southern mountain range in bad weather after taking off from Uganda.

“All indications as of now seem to indicate that it was an accident,” Secretary-General Annan told reporters here yesterday, calling for a calm response to the news.

This year’s agreement to end three decades of hostilities in southern Sudan established a unity government with participation by two rebel groups, including the SPLM. Yesterday, according to the Associated Press, Garang’s longtime deputy, Salva Kiir, was named as his successor to lead the SPLM. “From my discussions with the president of Sudan, I gained the impression that they are determined to proceed, and there is the same sentiment on the SPLM side,” Mr. Annan said.

The stakes are high. “The rioting and looting that have followed the announcement of Dr. Garang’s death threaten to further destabilize the situation if not brought under control,” one of the most prominent human rights organizations present in Sudan, the International Crisis Group, said in a statement.

The situation in Darfur, where hundreds of thousands died as victims of a Khartoum-backed campaign the Bush administration has defined as genocide, might also worsen in the wake of Garang’s death. American pledges for investment in infrastructure and other aid to Sudan hinges on a solution to the humanitarian crisis in the western region, Mr. Danforth said.

America and other members of the U.N. Security Council who visited Sudan last November hoped that the north-south agreement would ease tensions in Darfur as well. “I spoke to John Garang about Darfur in November,” Mr. Danforth said. “He made it clear that when there is peace between the north and south, he will work” on Darfur.

Some human rights activists in Sudan, however, are skeptical. “It’s not exactly clear how it’s going to happen,” Human Rights Watch’s Sudan point woman, Jemera Rone, told the Sun when asked about the link between the agreements and Darfur. The northsouth agreement, however, will most likely stick, she said: “The south wanted peace for a long time. They are not going to end it now just because Garang died.”