JUBA (AP) - Sudanese war planes have launched renewed air strikes against South Sudan, violating a UN Security Council resolution to end weeks of a bitter border conflict, the South's army said Wednesday.

"The Republic of Sudan has been randomly bombarding civilian areas," said Southern army spokesman Kella Kueth, who claimed the air strikes hit the border states of Upper Nile, Unity and Western Bahr el-Ghazal on Monday and Tuesday.

It was not possible to independently confirm the reports and Sudan has repeatedly denied it has bombed the South.

"The people of Khartoum, they just deny," Kueth said, adding that both fighter jets and Antonov airplanes carried out the air raids.

Both sides say they are complying with a United Nations Security Council resolution which ordered them to stop fighting from last Friday, amid international concern that the rivals could return to all out war.

Border clashes with South Sudan began in late March, escalating with waves of Sudanese air strikes against South Sudanese territory and the South's 10-day seizure of the Heglig oil field from Khartoum's army.

The South's army confirmed it had pulled back 10 kilometres (six miles) south of the contested border line, in accordance with the UN deadline Wednesday to do so. However the border is undemarcated.