People in southern Sudan have gone to the polls for the second day of a week-long referendum on the secession of the southern sector of the African country from the north.

People in southern Sudan have gone to the polls for the second day of a week-long referendum on the secession of the southern sector of the African country from the north. 

Polling stations opened on Monday as thousands of Sudanese were waiting to cast their vote in a referendum that could split Africa's biggest country in two, reported Taqrib News Agency (TNA).

In southern Sudan, some 3.75 million people are registered to vote, along with an approximate 117.000 in the north.

Sudanese leaders described the first day of the vote as "peaceful" and "successful" while long lines formed outside polling stations in the regional capital, Juba.

Southern Sudan President Salva Kiir called on the people to vote for a break of the south from northern Sudan.

"This is the historic moment the people of south Sudan have been waiting for," Kiir said on Sunday after casting his vote.

"Even if you cannot vote today, you have six more days to vote," he further explained.

A turnout of 60 percent is needed for the referendum to become valid. The referendum was part of a peace deal reached in 2005, which ended decades of conflict between the northern and southern sectors of the country.

Although Sudanese President Omar al-Bashir promised he would help south to gain its independence, he has warned that south Sudan would face instability.