On Friday, approximately 2,000 migrants stormed the heavily fortified border between the Moroccan region of Nador and the Spanish enclave of Melilla.
At least 23 migrants died and 140 police officers were wounded in the ensuing violence, according to Moroccan authorities.
It was the heaviest death toll in years of such attempts to cross the frontier into Melilla.
In a statement via Twitter on Sunday, AU Commission chairman Moussa Faki Mahamat said: "I express my deep shock and concern at the violent and degrading treatment of African migrants attempting to cross an international border from Morocco into Spain."
"I call for an immediate investigation into the matter and remind all countries of their obligations under international law to treat all migrants with dignity and to prioritise their safety and human rights, while refraining from the use of excessive force," he added.
Moroccan authorities say the individuals died as a result of a โstampedeโ of people who attempted to climb the iron fence that separates the city of Melilla and Morocco.
Moroccoโs Interior Ministry said 76 civilians were also injured.
Meanwhile, Spanish Prime Minister Pedro Sรกnchez condemned what he described as a โviolent assaultโ and an โattack on the territorial integrityโ of Spain.
Spanish officials said 49 Civil Guards sustained minor injuries.
โIf there is anyone responsible for everything that appears to have taken place at that border, it is the mafias that traffic in human beings,โ Sรกnchez said.
His remarks came as the Moroccan Association for Human Rights shared videos on social media that appeared to show dozens of migrants lying on the ground, many of them motionless and a few bleeding, as Moroccan security forces stood over them.
โThey were left there without help for hours, which increased the number of deaths,โ the human rights group said on Twitter.
It has called for a โcomprehensiveโ investigation.
In a statement released late Friday, Amnesty International expressed its โdeep concernโ over the events at the border.
The International Organization for Migration and UN refugee agency UNHCR also weighed in with a statement that expressed โprofound sadness and concernโ over what happened at the Morocco-Melilla border.
The mass crossing attempt was the first since Spain and Morocco mended relations after a year long dispute related to Western Sahara, a former Spanish colony annexed by Morocco in 1976.
The thaw in relations came after Spain backed Moroccoโs plan to grant more autonomy to the territory, a reversal of its previous support for a UN-backed referendum on the status of Western Sahara.
The African Union Commission chief has voiced his shock at the "violent and degrading" treatment of African migrants trying to cross from Morocco into Spanish territory after 23 people died, and has called for an investigation into the incident.
On Friday, approximately 2,000 migrants stormed the heavily fortified border between the Moroccan region of Nador and the Spanish enclave of Melilla.
At least 23 migrants died and 140 police officers were wounded in the ensuing violence, according to Moroccan authorities.
It was the heaviest death toll in years of such attempts to cross the frontier into Melilla.
Source: RFI
