(NewsNation) —  Ukrainian women and children fleeing Russia’s invasion are at risk for exploitation, officials say.

Over safety concerns, the United Nations told the UK to stop matching Ukrainian women with single British men who register as hosts offering refugees a room or a place to stay. A leading charity even described the UK’s homeless for Ukraine program as a “Tinder for sex traffickers” due to the lack of proper vetting of potential hosts.

Under the program, British residents connect with Ukrainian refugees directly, leaving tens of thousands of people to post on social media sites for hosts willing to take them in.

In issuing its warning, the UN High Commissioner for Refugees said there is a need for adequate safeguards and vetting measures to be in place against exploitation.

The UN’s move comes after widespread reports of female refugees being propositioned for sex by male hosts, not just in Britain but across Europe. According to The Times of London, some female refugees have reported being faced with sexual predators or kidnappers. They say often people offer them free rides into Poland and Germany only to later request sexual favors in return.

Suzanne Hoff develops counter trafficking strategies for La Strada. The international human rights organization works on the ground to assist and evacuate Ukrainian refugees. Thursday night, NewsNation host Dan Abrams asked Hoff about the UN’s warning.

Q: Talk to us about what these female refugees are facing.

A: There is actually increasing attention … by governments to warn women … about risks. So, there’s quite a bit of information at the border at the moment. But of course, we can never completely reduce the risks of people coming in contact with the wrong people having the wrong intentions.

Q: You say that some men seem to be using the situation as a way to try to find Ukrainian wives or girlfriends?

A: We always see with conflicts and wars that people with bad intentions, of course, try to reach out and to make profits off people, and especially vulnerable people. So we have seen this also with war before. Yeah, we have heard this not only in Ukraine, but also outside Ukraine, in particular, also Poland and in other countries. In the EU, we have heard that people offer housing (or) job offers, as well. Yeah, there is a risk and especially if people offer things and expect something in return, for example, sexual services, like you said.

Q: The UN has been speaking out specifically about this. Why do you think that they felt the need to make this public statement? I mean, it would suggest that they believe there is now a real concern about some of these charities in Europe.

A: I think one of the risks is, of course, that there’s so many women and children in particular leaving now, you see the men stay behind […] Of course, there are a lot of stories about it. There are not so many reports about people being exploited for traffickers. But (it’s) true that … everyone uses social media and online, you cannot completely control. So there are monitored offers. There are also the governments themselves trying to connect people and there are also registered organizations that do that. But you see a lot of private initiatives as well by people who want to support. And there of course, it’s very difficult to control whether those offers and those housing offers and employment offers are actually true, and whether they don’t lead to exploitation and abuse. That’s very difficult.