The U.N. refugee agency has urged authorities in countries neighbouring Ukraine to open their borders to African citizens fleeing the conflict there amid reports that some were being denied access to safety, UNHCR said on Wednesday.

Thousands of African and other foreign nationals, particularly students, have been scrambling to leave Ukraine since Russia’s invasion on Feb. 24.

Videos and testimonies have been circulating on social media complaining of discrimination against Africans at train stations and border posts. Journalists have not been able to authenticate these accounts.

Buchizya Mseteka, a South Africa-based UNHCR spokesperson, said the agency had not verified the reports but is urging countries bordering Ukraine to ensure that asylum and protection are made available to all.

The African Union has also said it was disturbed by reports that African citizens in Ukraine were being refused the right to cross borders to safety.

Ukrainian Foreign Minister Dmytro Kuleba said in a tweet that Africans seeking evacuation need to have equal opportunities to return to their home countries safely and that his country would help solve the problem.