Khartoum accused the Ethiopian Armed Forces of executing seven Sudanese soldiers and a civilian who were held captive, the Sudanese Armed Forces said in a statement on Sunday.

The Sudanese army also accused Addis Ababa of displaying the bodies of the execution victims to the public and vowed that there would be "an appropriate response" to the Ethiopian action.

"This treacherous act will not pass without a response," Khartoum said.

The Ethiopian authorities did not comment on the accusations directed from their northwestern neighbors.

Tensions have been soaring between Sudan and Ethiopia over the past few years due to the conflict in Ethiopia's northern Tigray region spilling over into Sudan and causing various issues within the country. 

The Ethiopian government also initiated the construction of a giant hydropower dam on the Blue Nile, the Renaissance Dam, which has been facing mounting scrutiny from Ethiopia's northern neighbors of Egypt and Sudan.

Kiffle Horo, project manager of the Grand Ethiopian Renaissance Dam (GERD), told Saudi Al-Arabiya News Channel in late May that the dam's third filling will not be delayed and will take place in August and September.

For over a decade, Egypt and Sudan have been negotiating with Ethiopia to obtain a legally binding and comprehensive agreement on the filling and operation of the GERD, which Addis Ababa began constructing on the Blue Nile in 2010.

Egypt is concerned that the GERD's unilateral operation and the filling of its 74-billion-cubic-meter reservoir will have a negative impact on its water supply, while Sudan is concerned that the GERD will harm the regulation of flows to its own dams and their safety. However, Ethiopia argues that the project would provide heaps of energy for the country.

Tens of thousands of Ethiopians have sought refuge in eastern Sudan, fleeing there to escape the war within their country. There have also been periodic clashes between the Ethiopian and Sudanese armies along the border between Sudan and Ethiopia.

Witnesses in Ethiopia on Sunday said that around 200 ethnic Amhara people were murdered in an attack in the country's Oromia region, accusing a rebel group, which denies it.