Sudanese government and southern rebel officials signed a permanent cease-fire deal Friday and endorsed a detailed plan on implementing a series of agreements to end a 21-year civil war in southern Sudan (search).

The truce will come into force some 72 hours after the deal was signed in Kenya's lakeside town of Naivasha, said Sayed El-Khatib, spokesman of the Sudanese delegation at the talks.

The deals clear the way for the warring sides to sign a comprehensive peace deal in early January in the Kenyan capital of Nairobi.

United Nations and U.S. officials hope a solution to the civil war will spur an end to the separate conflict between government-backed forces and rebels in the western Darfur region, where disease and hunger have killed 70,000 since March. Nearly 2 million are believed to have fled their homes since the start of the Darfur crisis (search).

U.N. Secretary-General Kofi Annan (search) welcomed the signing of agreements Friday, saying he looked forward to the final comprehensive deal "ushering in a new era of peace in Sudan, in which the United Nations is prepared to play a significant role," according to a statement.

After two years of peace talks, the civil war adversaries on Friday signed agreements on how they would implement protocols on sharing power and natural wealth, what to do with their armed forces during a six-year transition period, and on how to administer three disputed areas in central Sudan.

The protocols were signed during previous rounds of peace talks, but the warring sides had not spelled out how the deals would be executed, which government agencies would be responsible for implementation and how the deals would be funded.

Sudanese government and rebel officials wanted these issues detailed in the peace deal to prevent any side from stalling on implementation.

"We now have all the components that will form the comprehensive Sudan peace agreement," chief mediator Gen. Lazaro Sumbeiywo said. "Every topic on our agenda has been discussed and agreed on."

Sudanese President Omar el-Bashir, South Africa's President Thabo Mbeki and Kenyan Vice President Moody Awori observed the signing of the last main protocols that will form part of the final peace deal.

The north-south war has pitted Sudan's Islamic-dominated government against rebels seeking greater autonomy and a greater share of the country's wealth for the Christian and animist south. The conflict is blamed for more than 2 million deaths, primarily from war-induced famine and disease.

In Sudan's capital of Khartoum, thousands of southern Sudanese took to the streets, singing and waving rebel flags as government and the deals were signed in Kenya to end Africa's longest-running conflict.

"The peace deal is the beginning of real independence from Sudan," said Qamar Hasan al-Taher, a member of the main southern rebel group Sudan People's Liberation Movement. Sudan, which on Saturday celebrates its 1956 freedom from Britain, has been embroiled in a series of civil wars for most of its independence.

The southern rebel group's green, black, red, white and blue flag, with a golden star, appeared for the first time on the streets of the tightly controlled capital city, where demonstrators' songs blared on loudspeakers.