People in southern Sudan begin voting in a historic vote that will decide whether the country splits or remains united.
There is an air of celebration in Juba as southern Sudanese begin voting in an historic referendum to decide whether they want to secede from Sudan or remain united.
The week-long poll started on Sunday at 8:00 local time [05:00 GMT] across Sudan. It is also being held in eight other countries that have substantial numbers of southern Sudanese.
Among the first to exercise the choice was Salva Kiir, the president of southern Sudan.
Addressing the crowd after he voted, Kiir paid tribute to John Garang, who had led the south to a 2005 peace deal that ended a 22-year war with the north.
Garang died in a helicopter crash soon after the deal was signed.
"Dr. John Garang, and those that died with him in the struggle, are here with us today and we hope that they did not die in vain," Kiir said.
"This is the moment you have been waiting for," he told the crowd, asking them to have patience.
"Even if you cannot vote today, you can vote tomorrow."
Kiir said that in no way should the vote be jeopardised, telling the security forces to protect all the people, especially people from the north.
A total of 3.9 million southerners have registered for the self-determination vote that may lead to the partition of Africa's largest country.
The breakdown of the registrants is: southern Sudan, 3.7 million; northern states, 116,000; and the diaspora spread over eight countries, 60,000.
Earlier on Saturday, in an appeal to his people, Kiir urged them to behave in a peaceful and responsible manner during the referendum.
"This is a most important and decisive moment in your life. It is not the end of a journey, but the beginning of a new journey,” said Kiir referring to the Comprehensive Peace Agreement [CPA] signed by the north and the south that brought an end to the Sudanese civil war in 2005 and made the referendum possible.
"Today there is no return to war. There is no substitute for peaceful co-existence and it is critical for the coming generation," he said.
Hundreds of observers have flocked to Sudan to monitor the polls. Among them is John Kerry, the US senator who is there as President Barak Obama’s special representative.
Kerry watched Kiir cast his vote and said that the referendum represented a "new chapter" for Sudan.
Hollywood star George Clooney, also watched Kiir as he cast his ballot, and described the launch of the referendum as a "great day for all the world".
Many in the south will be voting before or after Sunday church services.
The church plays a prominent role in the life of southern Sudanese and the pulpit has been used to mobilise the population.
On the ground, to see firsthand that the referendum passes off without any incident, are 1,400 international observers spread across Sudan.
UN flights were busy throughout the past few days to take the observers to remote areas of a region the size of Texas state in the US.
Prominent among foreign poll observers will be Jimmy Carter, former US president, Kofi Annan, the former UN Secretary General, and Joseph Warioba, former Tanzanian prime minister.
The European Union has deployed a 110-strong team of observers. The team is comprised of members from 27 European countries as well as Switzerland, Norway and Canada.
South Africa, Japan, Russia and China have also sent observers.
The UN has also appointed a three-member panel to monitor the referendum. It is led by Benjamin Mkapa, another former Tanzanian president. This is in addition to observers from the African Union.
Security has been stepped up in the region with more than 60,000 personnel being deployed.
Biar Mading Biar, a police spokesman, told Al Jazeera that the police have extensively briefed about their duties for the referendum.
At a recent parade in police parade in Juba, Biar said "the peaceful conduct of the referendum is their mandate".
Chan Reec Madut, who heads the South Sudan Referendum Bureau, did not rule out extending the number of days if needed. He said this was because movement of people in remote areas was still a problem.
He said it was realistic to expect the results only three weeks after the last polling date.
Vote counting will be a done on a daily basis and results will be displayed at individual centres. While the preliminary results will be announced from Juba, the final result will be announced in Khartoum.
Madut hoped the voting will be as peaceful as the registration process.