The United States has strongly condemned an air strike against South Sudan's oil wells blamed on neighboring Sudan.
In a statement Thursday, State Department spokeswoman Victoria Nuland said such attacks on civilian targets are "deplorable." She said the U.S. "demands" the Sudanese government end its aerial bombardments, which it says violate international law.
A spokesman for Sudan's military, Sawarmi Khaled Saad, denied his country was behind the bombings.
South Sudan officials, including government spokesman Barnaba Marial Benjamin, say Sudanese warplanes dropped bombs Wednesday in an area of Unity State, about 75 kilometers from the two countries' contested border.
The officials say the bombardment destroyed two oil wells.
Marial said the attack violated a non-aggression pact Sudan and South Sudan signed in Ethiopia last month.
"...this is actually a violation of the non-aggression treaty that we signed two weeks ago and with the nature of Sudan's government, they don't always respect what they signed with anybody. We are not surprised," said Marial.
The south repeatedly has accused the north of violating its territory, and both sides have accused each other of supporting the other's rebels.
In her statement Thursday, Nuland also stressed South Sudan must cease any military support for rebels active in the north. She said both countries are "inflaming conflict," and "fueling mistrust."
The two countries are locked in a dispute over oil revenues. The south took over three-fourths of Sudanese oil production when it became independent last July, but relies on northern pipelines and facilities to send the oil abroad.
The north seized millions of barrels of oil after the south refused to pay what it considered excessive transport fees. The south has reacted by shutting down oil production, a move analysts say is bound to hurt both countries.
The dispute and simmering tensions over the border have raised fears the two Sudans are headed toward war. In the former unified Sudan, the north and south fought a bloody civil war that lasted 21 years.
Marial said Thursday that South Sudan will file a complaint about Sudan with the United Nations Security Council. Sudan filed a complaint about the South with the Security Council on Tuesday.