Police in Poland have warned that fake reports of violent crimes being committed by people fleeing Ukraine are circulating on social media after Polish nationalists attacked and abused groups of African, south Asian and Middle Eastern people who had crossed the border last night.

Attackers dressed in black sought out groups of non-white refugees, mainly students who had just arrived in Poland at Przemyśl train station from cities in Ukraine after the Russian invasion. According to the police, three Indians were beaten up by a group of five men, leaving one of them hospitalised.

“Around 7pm, these men started to shout and yell against groups of African and Middle Eastern refugees who were outside the train station,” two Polish journalists from the press agency OKO, who first reported the incident, told the Guardian. “They yelled at them: ‘Go back to the train station! Go back to your country.’”

Police intervened and riot officers were deployed after groups of men arrived chanting “Przemyśl always Polish”.

“I was with my friends, buying something to eat outside,” said Sara, 22, from Egypt, a student in Ukraine. “These men came and started to harass a group of men from Nigeria. They wouldn’t let an African boy go inside a place to eat some food. Then they came towards us and yelled: ‘Go back to your country.’”

Following the incident, police in Poland warned that groups linked to the far right are already spreading false information about alleged crimes committed by people from Africa and the Middle East fleeing war in Ukraine.

Przemyśl police said on Twitter: “In the media, there is false information that serious crimes have occurred in Przemyśl and the border: burglaries, assaults and rape. It’s not true. The police did not record an increased number of crimes in connection with the situation at the border. #StopFakeNews.”

According to the news website Notes From Poland, one Facebook group, named Przemyśl Always Polish (Przemyśl Zawsze Polski), has been spreading false claims that “economic migrants from the Middle East” were committing crimes, “including a knife attack on a young woman and numerous thefts from shops”.

The attacks on people fleeing the war come amid efforts by some African governments to evacuate their citizens who have passed into countries bordering Ukraine after reports of racist abuse and discrimination.

On Wednesday, Nigeria’s foreign ministry said it planned to start airlifting more than 1,000 Nigerians stranded in countries neighbouring Ukraine.

Many of the foreign nationals fleeing the Russian attacks are students. About 16,000 African students were studying in the country before the invasion, Ukraine’s ambassador to South Africa said this week.

Reports and footage on social media in the past week have shown acts of discrimination and violence against African, south Asian and Caribbean citizens while fleeing Ukrainian cities and at some of the country’s border posts.

In an interview with the Guardian, a 24-year-old medical student from Kenya, who did not want to be named, said she spent hours waiting for Ukrainian border guards to let her enter Poland because they were prioritising Ukrainian nationals.

After eventually crossing the border, she boarded a free bus, organised by an NGO, to a hotel near Warsaw that was offering free board to Ukrainian refugees. But the hotel refused to take her and her Kenyan friends in, even after she offered to pay for a room.

However, other foreign nationals interviewed by the Guardian said that they had been treated well by the Polish authorities, with many of the reports of racial abuse occurring on the Ukrainian side of the border.

The Nigerian president, Muhammadu Buhari, said on Monday: “All who flee a conflict situation have the same right to safe passage under the UN convention and the colour of their passport or their skin should make no difference,” citing reports that Ukrainian police had obstructed Nigerians.

“From video evidence, first-hand reports, and from those in contact with … Nigerian consular officials, there have been unfortunate reports of Ukrainian police and security personnel refusing to allow Nigerians to board buses and trains heading towards Ukraine-Poland border,” he said.

On Tuesday, Ukraine’s foreign minister, Dmytro Kuleba, acknowledging the allegations, said: “Ukraine’s government spares no effort to solve the problem.”

“Africans seeking evacuation are our friends and need to have equal opportunities to return to their home countries safely,” he said in a statement on Twitter.

Ghana, South Africa and Ivory Coast are also among a growing number of African countries seeking to evacuate their citizens in response to reports of discrimination and violence that have sparked widespread outrage.

Some African governments are making plans to evacuate citizens who have passed into countries bordering Ukraine after reports of racist abuse and discrimination.

In Nigeria, Gabriel Aduda, permanent secretary for the ministry of foreign affairs, said three jets chartered from local carriers would leave the country on Wednesday, with the capacity to bring back nearly 1,300 people from Poland, Romania and Hungary.

Rights groups have welcomed the efforts by Poland to help, but some drew comparisons with the treatment of other refugees from Syria, Afghanistan and Kurdish Iraqis in the country, where the populist rightwing government has often played on anti-refugee sentiment.

Last year, after the Belarusian president, Alexander Lukashenko, organised the movement of refugees with the promise of a safe passage to Europe, thousands of people from the Middle East were caught by Polish border guards in the forests near the border and illegally and violently pushed back to Belarus.