Juba, South Sudan (CNN) -- South Sudan accused Sudan of launching ground and aerial attacks inside South Sudan's territory Sunday.
"There have been bombings since 9 this morning, and at 1 o'clock they launched a ground attack," said Barnaba Marial Benjamin, South Sudan's minister of information.
The clashes came after the southern army said it withdrew troops from a contested, oil-rich border region.
A spokesman for the Sudanese military could not be immediately reached for comment. Claims from both sides are difficult to confirm, as journalists and independent observers do not have access to the front lines.
South Sudan announced Friday that it would comply with a request from the United Nations Security Council to pull troops out of the disputed oil-rich region of Heglig, which it had occupied since April 10. Sudan claimed its forces had forced southern troops out and captured the area.
Benjamin said his country's army withdrew to bases near the border and inside South Sudan. Sudanese forces crossed the border and attacked them there, he said.
"They are trying to drag us back into a war, and that's what the Security Council didn't want," he said. "They must tell them to stop these attacks."
Benjamin said the bases near the border have been repeatedly attacked in the past by Sudanese troops based in Heglig, and those previous attacks prompted South Sudan to occupy the area.
Heglig is on the border created last year when the two countries split.
Sudanese President Omar al-Bashir had vowed to "never give up" the disputed region.
While both countries claim Heglig, Sudan continued administering the region after South Sudan declared independence last July following a two-decade civil war.
The south took with it three quarters of the formerly united country's oil reserves, a loss that sent Sudan's economy reeling.
Sudan's oil industry suffered further when fighting in Heglig forced a halt to oil production in those fields, which account for about half of the country's entire production of 115,000 barrels a day. Satellite images suggest that infrastructure in the Heglig oil fields may have been severely damaged by the fighting.
The Satellite Sentinel Project released images Sunday that suggest a critical part of the oil pipeline infrastructure was destroyed. The collection manifold, which allows oil flows to be separated or combined without interrupting the flow, appears to have been damaged by an explosion.
"The evident destruction of the collection manifold is a big deal in that this by itself is likely to result in immediate cessation of oil flow from the area," said Jonathan Hutson, a spokesman for the project, which is led by the Harvard Humanitarian Initiative.
Hutson said analysts could not determine whether the destruction was the result of ground fighting or aerial bombardment.
On Friday, South Sudan's military spokesman, Philip Aguer, told reporters in Juba that Sudan had bombed Heglig's central processing facility the previous day and that it continued to burn.
Serious damage to the facility would prevent companies from resuming production and would require substantial investment to repair or rebuild.
Sudan has accused South Sudan of destroying oil infrastructure and said it would attempt to force South Sudan to pay for damages.
The renewed fighting follows an appeal Saturday by U.S. President Barack Obama, urging the countries to "choose peace" and return to negotiations.
"You still have a chance to avoid being dragged back into war," he said in a video, which was subtitled in Arabic and posted to the White House website.