Referendum voting began on January 9, 2011 and will last one week [Al Jazeera]

South Sudan's referendum, to determine whether the region splits from the rest of the country, has on Wednesday passed the 60 percent threshold for the poll results to be valid, marking a crucial step in the separation process.

A senior official in southern Sudan has confirmed that more than 60 percent of registered voters have already cast their ballots as the fourth day of independence referendum gets underway.

Officials in the Khartoum-based government have yet to respond to this claim.

The result of the voting, widely expected to go in favour of a north-south separation, can now be considered valid once the they are counted.

The predominantly animist and Christian southerners have long blamed the mostly Arab and Muslim north of exploiting the South's oil without investing revenue in its development.

Southerners were also angered by the north's attempts to impose Islamic law across the country.

The votes for independence will not be finalised until July ,and Sudan has much to figure out in the meantime.

Sudanese President Omar Al-Bashir has said he would let the South secede peacefully, but the split of Africa's largest country would deprive the north of most of its oil fields, which means north-South oil rights will have to be renegotiated.

Other issues include water rights to the White Nile, border demarcation and the status of Abyei, a disputed north-South border region with the most imminent threat of a return to conflict.

Although voting has largely been peaceful and even jubilant, officials have said that violence in Abyei has killed at least 30 people in recent days.

Source: Agencies