The Sudanese President, Omar al-Bashir, arrived in the disputed border area between the two Sudans yesterday, vowing that there would be no peace talks as forces loyal to Khartoum bombed targets inside South Sudan's territory.
Ignoring international appeals for restraint, the Sudanese leader, who is wanted for war crimes by The Hague, told troops in the contested oil town of Heglig that the South understood "nothing but the language of the gun".
Earlier in the day, war planes dropped bombs more than five miles inside South Sudan where they hit a marketplace killing one boy and injuring 10 other people. The South agreed last week to withdraw its forces from the Heglig oil fields they had taken earlier this month, following heavy pressure from the United Nations and the US.
Despite recent fighting over the oil fields at Heglig and the bellicose rhetoric, most analysts think the two Sudans will stop short of a return to all-out war. Talks designed to finalise the border following the north-south divorce have broken down and both sides have massed forces near to disputed territories. But there is a suspicion that the brinkmanship is aimed at improving negotiating positions when talks do restart.
However, there were worrying signs over the weekend that the clashes are stoking ethnic and religious tensions in Khartoum, where a Muslim mob attacked a Christian church compound used by southerners. The attackers ransacked buildings and burned bibles on Saturday, a church official told Reuters.
The South's capture of Heglig, which supplies half of the north's oil, embarrassed the regime in the north, which is already battling rebels on three fronts. Khartoum has presented South Sudan's withdrawal from the oil fields as a military victory and pro-government forces celebrated the "recapture" of the area.
Mr al-Bashir, who has faced student protests in the northern capital inspired by the Arab Spring, has staged rallies where he has vowed to reconquer the south less than a year after it gained independence. "We will not negotiate with the South's government," he told soldiers at a barracks in Heglig yesterday.