Nigeria, South Africa and other African governments have scrambled to help their citizens escape the Russian invasion in Ukraine after reports of racist and unfair treatment of Africans at border crossings.
Africans in Ukraine, many of them students, are among hundreds of thousands of people trying to flee into Poland and other neighbours.
African Union leaders voiced concern at the reports of mistreatment of Africans caught up in the Ukraine conflict and said such conduct would be "shockingly racist".
The current chair of the African Union, Senegalese President Macky Sall, and African Union Commission head Moussa Faki Mahamat said on Monday that they were "particularly disturbed by reports that African citizens on the Ukrainian side of the border are being refused the right to cross the border to safety".
"Reports that Africans are singled out for unacceptable dissimilar treatment would be shockingly racist and in breach international law," they said in a statement.
All countries should "respect international law and show the same empathy and support to all people fleeing war notwithstanding their racial identity", they added.
Nigeria's Foreign Minister Godfrey Onyeama said on Monday the evacuation of the country's nationals would start on Wednesday.
Earlier, presidential adviser Garba Shehu had urged Ukrainian border officials to treat Nigerian citizens equally after reports they had been stopped from boarding buses and trains to the border.
Mr Shehu referenced a video on social media showing a Nigerian mother with a young baby being physically forced to give up her seat.
There had been also reports of Polish officials refusing Nigerian citizens entry into Poland from Ukraine, he added.
"All who flee a conflict situation have the same right to safe passage under UN Convention and the colour of their passport or their skin should make no difference," said Mr Shehu.
'Kept outside'
South African foreign ministry spokesman Clayson Monyela meanwhile tweeted that a group of his country's nationals, mainly students, was stuck at the Ukrainian-Polish border.
The South African ambassador to Poland was at the site trying to get them through, he added. On Sunday, Mr Monyela said Africans were being "treated badly" at the Polish-Ukraine border.
Poland's ambassador to Nigeria Joanna Tarnawska dismissed claims of unfair treatment.
"Everybody receives equal treatment. I can assure you that I have reports that already some Nigerian nationals have crossed the border into Poland," she told local media.
Nigerians could stay for 15 days and even invalid documents were being accepted to cross the border and COVID-19 restrictions were lifted, she said.
Some Nigerians who made it across the borders described having been made to wait as officials gave priority to Ukrainian women and children.
"One of the officers came and told us it's harder for us foreigners because they have to get in touch with our government in different countries," Stephanie Agekameh, a medical student now in Poland, said by text message.
Speaking from Korczowa in Poland, Nigerian managerial sciences student Agantem Moshe said Ukrainian police had pushed Africans out of the way to make way for women and children.
"From the Polish side it was smooth, they were professionals. In Ukraine, they kept us outside in the cold," he said.
The UN said that more than half a million refugees from Ukraine had so far crossed into neighbouring countries.
Nigeria's embassy in Bucharest said it had received 130 Nigerians from Ukraine, with more being processed having reached Warsaw or Budapest.
'Priority to Ukrainians'
Ghana's government said it would meet parents of students stuck in Ukraine on Tuesday and sent embassy officials to border points to help.
DR Congo Foreign Minister Christophe Lutundula said on Twitter he would meet with the Polish ambassador to help with the passage across the border of about 200 Congolese, mostly students.
Ivory Coast, which according to state media has 500 nationals in Ukraine, said it was also making arrangements for their evacuation from the country.
Kenya's foreign affairs ministry said last week around 200 Kenyans were safe and accounted for but that some were stuck at the Polish border because of visa restrictions.
Nigerian accountant Lukmon Busari said his son, a fourth-year medical student, was already out after waiting for a day on the Polish border.
"Initially they didn't allow them to move as they gave priority to Ukrainians, to women and children. Eventually they allowed them into Poland," Mr Busari told AFP by telephone.
According to him, the Polish authorities "did a marvellous job".
