Sudanese armed forces launched an attack more than nine kilometres inside South Sudan's border, an official said Sunday, days after the south announced it was pulling its troops from a disputed border town to avoid an all-out war between the two countries.

Ground troops from Sudan launched three waves of attacks, Deputy Director of Military Intelligence for South Sudan Maj. Gen. Mac Paul said.

A soldier's body and two wounded soldiers were brought to a hospital, the clinical director at the Rubkona Military hospital, Dr. Zecharia Deng Aleer, said. Aleer said the soldiers were brought in from around the Pariang Junction, in South Sudan's Unity State.

Paul said it was the first major engagement between the two armies since South Sudan announced it would pull out from the contested border town of Heglig.

Paul said the Sudanese forces "have come deeply in the south" and attacked with artillery and tanks. He said the attack was part of a "continuous provocation from the Sudanese Army." Paul said Sudan also used "militias" in the attack.

Sunday's military attack came hours after a Muslim mob burnt a Catholic Church in Sudan frequented mostly by South Sudanese. The church in Khartoum's Al-Jiraif district was built on a disputed plot of land, but the Saturday night incident appeared to be part of the fallout from ongoing hostilities between Sudan and South Sudan over Heglig.

Witnesses and several newspapers said a mob of several hundred shouting insults at southerners torched the church. Fire engines could not put out the fire, they said.

Sudan and South Sudan have been drawing closer to a full-scale war in recent months over the unresolved issues of sharing oil revenues and the disputed border.

The international community, led by the U.S., has called for the two countries to stop all military actions against each other and restart negotiations to solve their disputes.

President Barack Obama on Friday asked the presidents of Sudan and South Sudan to resume negotiations and said that conflict is not inevitable.

Talks between the two countries over the unresolved disputes that were being mediated by the African Union, broke down in Ethiopia earlier this month.

The African Union on Sunday called on Sudan and South Sudan to end "senseless fighting."

"The commission urges the two parties to immediately and unconditionally resume negotiations ... to reach agreements on all outstanding issues," AU Commission Chairman Jean Ping said in a statement.

Last week, South Sudanese troops seized Heglig, which the southerners call Panthou, sending Sudanese troops fleeing. The Khartoum government later claimed to have regained control of the town.

A U.S. monitoring group said Sunday satellite imagery appear to shows the fighting around Heglig had caused major damage to oil pipeline infrastructure

The Satellite Sentinel Project said the images shows severe damage and in such a critical part of the oil infrastructure, that it would likely stop oil flow in the area.

South Sudan broke away from Sudan July last year after an independence vote, the culmination of a 2005 peace treaty that ended decades of war that killed more than 2 million people. Despite the treaty, violence between the two countries has been on the rise.