Khartoum, June 17 (IANS): The South Sudanese army on Wednesday accused Sudan air force of bombing areas in the Upper Nile state, killing six civilians and injuring nine others, according South Sudan's army spokesman.

"The Sudanese air force launched airstrikes against the Panis and Adham areas of Renk county in the Upper Nile state," Philip Aguer, South Sudan's army spokesman, told South Sudanese media on Wednesday.

He added that the Sudanese air force also launched airstrikes against different areas in Maban county in the Upper Nile state, Xinhua new agency reported.

"Those airstrikes killed six civilians, four of whom were children, and injured nine personnel of South Sudan's army," he noted.

"We were unable to contact the Sudanese army to discern the reason behind bombing South Sudan's territories," Aguer further said.

He urged the Sudanese army to stop violating South Sudanese territories, saying, "We urge the Sudanese army to work towards joint cooperation and cease the aggression in order to create stability for the border areas and populations of both countries."

The Sudanese army spokesman could not be immediately reached for comment on Juba's accusations.

Sudan and South Sudan are exchanging accusations of supporting rebel groups in each other's country, as both sides failed to define their joint border with each side claiming sovereignty over the disputed border areas.