Juba - South Sudan's military spokesperson says Sudan has launched at least four attacks against its southern neighbour.
Colonel Philip Aguer said on Thursday that all four attacks were repelled. Three of the attacks were on Wednesday and one was on Thursday. He did not give a death toll.
South Sudan broke away from Sudan last year after a self-determination vote for independence. That vote was guaranteed in a mediated end to decades of civil war between the two sides.
The two countries have seen a sharp increase in violence in recent weeks, especially around the oil-producing town of Heglig.
A South Sudan government spokesperson said on Thursday that the south does not consider itself at war with Sudan. He called Sudan a neighbour and a "friendly nation".