Egypt has denied allegations from Sudanese paramilitary chief Mohamed Hamdan Daglo, at war with the army since April last year, that its military has been involved in the conflict.
The war between Daglo's Rapid Support Forces and the regular military, led by army chief Abdel Fattah al-Burhan, has killed tens of thousands and caused the world's largest displacement crisis.
In a video posted online Wednesday, Daglo accused Egypt's air force of carrying out strikes targeting his forces near Jebel Moya, a key area south of Khartoum.
"Egypt is fighting us," he said, accusing it of being one of six countries of interfering in the conflict, including Iran.
Iran's supply of Mohajer-6 drones, verified by two weapons experts to AFP, appeared to give the army support for an advance on the Sudanese capital earlier this year.
In a statement issued late Wednesday, Egypt's foreign ministry rejected Daglo's claim.
Egypt "denies the allegations... regarding the participation of the Egyptian air force in the battles taking place in brotherly Sudan," the statement said.
Army chief Burhan has historically been close to Egyptian President Abdel Fattah al-Sisi.
Analysts say war-torn Sudan war has become a playground for proxies, warning in particular about the impact of the United Arab Emirates' support for the RSF.
In December, UN experts monitoring an arms embargo on Sudan's Darfur region described as "credible" allegations Abu Dhabi had funnelled weapons to Daglo's forces on cargo planes.
According to diplomats, the United States recently pressed the UAE behind closed doors over its support for the RSF, though US President Joe Biden designated Abu Dhabi as a "major defence partner".
Both the army and the RSF have been accused of repeated atrocities in the war, including targeting civilians, the indiscriminate shelling of residential areas and looting or blocking aid.
The RSF has been accused of crimes against humanity, systematic sexual violence and ethnic cleansing.