The UN human rights agency has welcomed a court decision to suspend a ban in one French resort
The United Nations says bans on burkinis in parts of France are "stimulating polarisation" between communities.
Around 30 French towns have outlawed the full-length beachwear.
Last week, France's highest administrative court suspended the ban that had been in effect in the resort of Villeneuve-Loubet.
The ruling is only temporary, and will give the court enough time to prepare a longer judgement.
The appeal was brought by the Human Rights League and a group campaigning against Islamophobia.
Several prominent French politicians have come out in support of the bans, including prime minister Manuel Valls and presidential candidate Nicolas Sarkozy.
Rupert Colville, spokesperson for the UN High Commissioner for Human Rights (OHCHR), says his office welcomes the court decision.
He said the rule is a "grave and illegal breach of fundamental freedoms", and noted that the agency is calling for all other burkini bans to be repealed.
In a statement, he explained: "These decrees do not improve the security situation but rather fuel religious intolerance and the stigmatization of Muslims in France, especially women. By stimulating polarisation between communities, these clothing bans have only succeeded in increasing tensions and as a result may actually undermine the effort to fight and prevent violent extremism, which depends on cooperation and mutual respect between communities.
"Dress codes such as the anti-burkini decrees disproportionately affect women and girls, undermining their autonomy by denying them the ability to make independent decisions about how to dress, and clearly discriminate against them."
The statement adds that the manner in which the bans have been implemented in some resorts "has been humiliating and degrading".