Dozens of women — many, if not most, from Africa and the Middle East — have been denied U.S. visas needed so they could attend a major UN women’s conference in New York, according to Buzzfeed.

Lyndal Rowlands, an “advocacy officer” with a UN-accredited civil liberties group, told BuzzFeed that women from countries that fell under the Trump administration’s travel ban were disproportionately affected.

The International Service for Human Rights, a UN-affiliated organization, said at least 41 women have been denied visas to attend the annual Commission on the Status of Women conference — but this figure is thought to be only “the tip of the iceberg” and likely to grow, Buzzfeed says.

It notes that “a 70-year-old treaty” requires the U.S. “not to restrict people or NGOs” from attending events at UN headquarters.

Reporting from New Delhi, Buzzfeed correspondent Nishita Jha says women’s rights activists have mounted a protest, petitioning the U.S. Mission to the UN “to streamline visa procedures for those traveling to the UN.”

According to the protest petition, there has been an “unprecedented” number of visa denials for women hoping to attend CSW, which is taking place now (Mar. 11-22). Buzzfeed describes it as an event at which “representatives from member states, NGO workers, and women’s rights activists gather to evaluate the global progress on gender and equality.”

According to the petition, women seeking to attend CSW from countries like Iran, Sudan, Zimbabwe, and Syria were asked to provide more-than-usual documentation, including marriage certificates, proof of property ownership, letters stating employment status, proof of finances, and even proof of birth certificates or proof that they have children.

At a CSW town hall meeting, a delegate from Zimbabwe asked UN Secretary-General António Guterres why women from rural backgrounds — who were depicted on UN banners and offered as “case studies” — weren’t permitted to attend and speak for themselves.