Sudan's army and its rival paramilitary the Rapid Support Forces blamed each other for the bombing on Tuesday of the Ethiopian embassy in the Sudanese capital.
The army and the RSF have been locked in ruinous fighting in the capital Khartoum and elsewhere in Sudan since mid-April, creating a massive humanitarian crisis and forcing millions to flee their homes.
The RSF was the first to level the accusation against the army, saying the "barbaric act" caused substantial damage to the embassy, located in the upscale Amarat district.
“We, in the Rapid Support Forces, condemn and regret this barbaric act.”
The army countered the RSF accusation in a statement of its own several hours later, saying the "mutinous" RSF was behind the attack.
"The armed forces condemn in the strongest terms this attack on the offices of the (Ethiopian) mission and express its deepest regret," said the army statement.
There was no comment immediately available on the attack by the Ethiopian government.
It was also unclear whether there were any casualties.
The army, led by Gen Abdel Fattah Al Burhan, has been using air strikes and heavy artillery in its fight against the RSF in the Sudanese capital, actions believed to have caused hundreds of casualties among civilians since the fighting began.
The RSF, whose forerunner is a notorious Darfur-based militia once known as the Janjaweed, is accused of large scale looting in the capital as well as gross abuse of civilians. In Darfur, the RSF and allied Arab militias are accused of targeting members of ethnic African communities, killing thousands and forcing many more to flee their homes.
The International Criminal Court has said it was investigating suspected war crimes by the RSF in Darfur.
Separately, the United States, Britain, Norway and Germany plan to submit a motion to the UN Human Rights Council to set up an investigation into alleged atrocities in Sudan, a draft motion showed on Friday.
The fighting has forced more than five million people to leave their homes, including about one million who took refuge outside Sudan, mostly in neighbouring nations.
Millions more are trapped in the Sudanese capital, enduring lengthy water and power cuts, scarce health care and skyrocketing food and fuel prices.
The early days of the fighting saw RSF fighters storm and vandalise foreign embassies and the offices of international organisations.