Sudan's southerners started casting ballots Sunday to decide the fate of unity or division of the African's largest country where two-decades of north-south war claimed two million lives.

A majority of registered voters are estimated to vote for seceding Sudan's Christian-Animist south from the mostly Muslim north in the week-long referendum, a major item in the 2005 Comprehensive Peace Agreement (CPA) inked between the two sides.

Voters lined up for hundreds of meters to wait for the beginning, which many say is a historic moment for Sudan. Women danced and sang slogans of "Freedom is burning" ahead of the referendum.

The vote started at polling centers in both south and north at 8:00 a.m. local time (0500 GMT) and will last at 5:00 p.m. (1400 GMT) till its expected end on Jan. 15.

Salva Kiir Mayardit, first vice president of Sudan and president of the government of South Sudan, cast the first ballot in Juba at a polling station at the museum of John Garang, founder of the Sudan People's Liberation Movement (SPLM), the south's ruling party.

The security of voting centers must be guaranteed, he said after the voting. "Security forces in the south and north Sudan must make sure the security of the voting."

He noted that the property of the northern Sudanese and foreigners in south Sudan must be protected, which won applauses among the cheering crowd.

The southern Sudanese residing in north and south Sudan and overseas have the right to participate in the referendum where 60 percent of the registered voters should cast their votes for the referendum to be valid.

If the southerns voted for independence, Sudan would enter a six-month transition period when the north and south would negotiate on thorny issues including border demarcation, the status of the oil-rich Abyei region, as well as the division of the national debts and oil revenue.

Almost 4 million people registered for the referendum, 95 percent of whom live in south Sudan, while others live in the north and eight countries including Kenya, Egypt, Ethiopia, and the U.S.A.

John Kerry, chairman of the United States Senate Committee on Foreign Relations, told Xinhua while he observed the voting process, "I'm very excited. It's very important. I hope it will be a peaceful referendum."

Asked about the controversial issues including border, oil and Abyei, Kerry said, "I think the controversial issues can be resolved within the six-month transition period as we work in good faith."

Around 17,000 local observers together with 1,200 foreign observers are currently monitoring the south Sudan referendum to assess its compliance with the international standards.

Trained polling staff directed voters to check their identity cards and illustrated how to cast ballots as 92 percent of the southern residents are illiterate. Young men and women wearing shirts with slogans "Vote peacefully" and "Vote for freedom" marched in Juba streets.

Deng Ayok, a 28-year-old university student who suspended his study in Khartoum, Sudan's capital, and returned to the south in November, led his family to vote at Juba University Sunday morning.

The civil war forced him to become a refugee at three years old. His mother fled with him to Ethiopia, while his father joined the army of the SPLM to fight in the bush for 20 years.

"I hope the referendum can reflect our will and lead to a permanent peace and stability of all Sudanese people," he said. " We had suffered so much during the civil war. We need dignity and human rights in a peaceful and stable land."

Barnaba Benjamin, minister of information and spokesman of the southern Sudanese government, expressed his confidence in an interview with Xinhua on Saturday that the southern Sudanese would vote for the independence of the region in the referendum.

He held the successive northern governments responsible for failure to boost the emotion for unity among the southern Sudanese citizens since country's independence in 1956.

But leading member of the ruling SPLM affirmed that the emerging southern Sudan state, in case of separation, would not be hostile to north Sudan and it would never seek war.

In a speech on Saturday, Kiir urged voters to "behave in a peaceful and respectful manner" and reiterated that there is no return to war.

"The referendum is not the end of the journey but rather it is the beginning of a new one. There is no substitute to peaceful co- existence, cooperation and partnership which we shall and are all committed to embark on in the lifetime ahead," Kiir said.

About 117,000 southerners who live in the north also registered to vote, but some polling stations were almost empty, compared with the enthusiasm of flocking people in the south.

In Khartoum, the first hour of voting registered low turnout at polling centers, Badr-Eddin Hiraiz, director of the al-Gerif Shareg polling center in eastern Khartoum, told Xinhua.

By 9:00 a.m. local time (0600 GMT), only one southern Sudanese voted at the center, the biggest in the capital, with was expected to receive 1,088 registered voters, he said.

"There are many reasons behind this weak turnout," he said, " including the wave of cold which hit the capital today, and the fact that most of the southerners work at farms, factories and do other freelance works. It is difficult for them to abandon their work to come to the polling centers."

Hiraiz expected the turnout to increase by midday.

Some northern Sudanese people still bear a ray of hope for unity.

"Why separation? We (the north and the south) are one nation. The northerners and the southerners can live together peacefully," 30-year-old Sayed Radi, a mobile shop owner in Khartoum said before the referendum. "The separation of the south will make our country weaker, as we will lose a lot of oil."

As the referendum went smoothly in most parts of the country, clashes were going on in the disputed border region of the oil- rich Abyei.

At least nine civilians of Ngok Dinka people were killed in the past three days as Sudanese armed forces and militia attacked villages in Abyei, said Deng Mading, acting chairman of the Abyei Referendum Forum at a press conference in Juba on Sunday.

The attack aimed to disturb the referendum, he said, adding that the northern troops and the local police in Abyei were still fighting as of Sunday and the casualties could rise.

People in Abyei were promised a referendum, also on Jan. 9, on whether to join the north or south, but the plan was postponed, leaving both sides with a thorny task of settling the region's future status through negotiations.

"There is still time for Abyei," Mading said. "We call upon President Bashir and President Kiir to sit together and recommit themselves to the final resolution of Abyei which is provided for in the CPA."

A Christian voter, who gave his name as Karafino, said he just finished a 40-day fasting with hundreds of fellows before the eve of the referendum.

"We fasted for the referendum, and we pray for peace during and after the referendum," he said while waiting at a polling station. "There are so many tough issues ahead after we vote. We need wisdom and a good government to solve the problems and develop ourselves. May God bless us."