The Sudanese government is accusing Chad of sending troops into Darfur to supply rebels in the region.
Sudan's Information Minister Kamal Obeid issued a statement Wednesday saying Chadian troops took supplies to the rebel Justice and Equality Movement near the North Darfur capital of El-Fasher. He also accused Chad of providing protection to the rebels.
The Reuters news agency quotes a statement from Chad's communications minister denying the accusations.
Chad and Sudan broke off diplomatic relations last year, with each accusing the other of supporting rebel assaults on their capitals.
The countries re-established relations in November, but tensions between the two nations remain high. On Monday, Chad accused Sudan of supporting the formation of a new insurgent group opposed to the Chadian government.
Some information for this report was provided by AFP