UN Secretary General António Guterres has joined in the chorus of condemnation after at least 23 migrants died as Moroccan security forces tried to stop them crossing into the Spanish enclave of Melilla last week.
In a statement issued on Twitter, he said he was "shocked by the violence".
"The use of excessive force is unacceptable, and the human rights and dignity of people on the move must be prioritized by countries," he added.
Between 1,500 and 2,000 migrants who had been camping in the Moroccan mountains surrounding Melilla descended on the city's border last Friday, a number of them carrying sticks, hoping to scale the border fences and therefore reach Spanish territory.
In the chaos that followed, many of them were crushed between the six-metre-high fences and Moroccan border guards, who used tear gas and batons on the migrants.
The Moroccan authorities say a number of people were crushed to death in a stampede on Friday after a section of border fence was cut open, while others may have been killed after falling from a border fence.
Spanish Prime Minister Pedro Sánchez has blamed people traffickers.
But the incident has provoked protests in Spain, with demonstrators saying the government's hard-line policies are forcing migrants to take desperate measures.
A lawyer for the former Tunisian Prime Minister Hamadi Jebali, says his client has been released by a judge, four days after he was detained on suspicion of money laundering.
Mr Jebali had gone on hunger strike to protest against his detention and had been taken to hospital on Saturday.
During his premiership from 2011 to 2013, Mr Jebali belonged to the Ennahda Islamist party - the largest in parliament until President Kaïs Saïed dissolved the assembly and seized executive power in Tunisia last year.
The party had said his arrest was part of a campaign of settling political scores.