Sudan’s ceasefire has been broken as rebels have attacked South Sudan’s army.

According to a report by the BBC, at least 16 people have been killed when forces loyal to George Athor blew up two army trucks near the town of Fangak in Jonglei state.

Southern army spokesman Philip Aguer was quoted as saying that four soldiers and 12 rebels were killed, but he feared many more people had died.

Athor took up arms last year, alleging fraud in state elections, but signed a ceasefire last month. The clashes come as Southern Sudan prepares to secede from the north following the preliminary results of January’s referendum.

More than 99 per cent of votes in Southern Sudan were cast in favour of secession from the country’s northern region.

A total of 3,837,406 votes were cast. While opinion in the country’s North was more divided with 42.4 per cent voting for unity, 99.6 per cent of Sudan’s Southern voters opted for secession.

Due to the much higher population in the South – with 3,724,194 votes cast in the South compared with 69,597 in the North – the overall vote in favour of secession stands at 98.83 per cent.

The poll was agreed as part of a 2005 peace deal to end two decades of war along religious and ethnic lines between the predominantly Islamic North and Christian South.