(CNN) — Sudanese war planes crossed a disputed border region to conduct airstrikes in South Sudan on Monday, a witness said, escalating fighting that threatens to return the neighboring African countries to full-scale war.
The report of the bombing of the towns of Bentiu and Rubkona comes days after South Sudan pulled its troops at the request of the United Nations from the disputed, oil-rich region of Heglig, though Sudan claims its soldiers retook the area from South Sudanese soldiers.
Two fighter jets fired four missiles at the neighboring towns, divided by a river, hitting an open air market and killing at least one person, said journalist Alan Boswell, who is in Bentiu.
Boswell was in his car crossing the bridge between the two towns when anti-aircraft fire erupted. That was followed, he said, by missile strikes.
“I saw one boy who about 10-years-old, who was completely burned,” he said by telephone. “There are other casualties.”
The remains of thatch-covered stalls in Rubkona smoldered for hours after the bombing, which occurred in the morning, Boswell said.
In the hours following the airstrikes, Boswell said the military presence in the area increased. Two South Sudanese generals who were arriving near the towns said the airstrikes were “a clear escalation” by Sudan, he said.
In addition to the airstrikes, South Sudan’s military spokesman, Philip Aguer, said fighting continued Monday in several areas of the border region.
South Sudan has accused its northern neighbor of repeatedly crossing its border since Sunday to launch ground and aerial attacks.
A spokesman for the Sudanese military could not be immediately reached for comment. Claims from both sides are difficult to confirm, as often journalists and independent observers do not have access to the front lines.
But on state-run TV, a Sudanese government spokesman said Khartoum would respond to South Sudan’s use of force with its own force.
The latest attacks come after Barnaba Marial Benjamin, South Sudan’s minister of information, said his country’s army withdrew from Heglig to bases near the border and inside South Sudan. Sudanese forces crossed the border and attacked them there over the weekend, 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 take the area on April 10.
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 further suffered 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 two countries have accused the other of being behind the destruction.
Sudan has accused South Sudan of destroying oil infrastructure and said it would attempt to force South Sudan to pay for damages; South Sudan has said Sudan bombed Heglig field’s central processing facility.
Serious damage to the facility would prevent companies from resuming production and would require substantial investment to repair or rebuild.
The renewed fighting follows a weekend appeal by U.S. President Barack Obama, urging the countries to “choose peace” and return to negotiations.