Shocked South Africans have taken to social media to voice their outrage that Ryanair is making some passengers take a test in Afrikaans in order to fly. Last week, the airline started asking passengers flying into the U.K. on South African passports to take the test to prove their nationality, in the language spoken by less than 20% of South Africa's population.

Zulu is the most widely spoken language in South Africa, at more than 20%, followed by Xhosa and then Afrikaans at 13%.

Ryanair defended the policy, saying in a statement that the test was put in place due to the "high prevalence of fraudulent South African passports."

But the relatively low prevalence of Afrikaans speakers in the country led many to wonder on social media why the airline had chosen to test people in the language imposed by South Africa's long-ousted, colonial white minority rulers during the days of Apartheid.

One Twitter user slammed the airline, writing: "Seriously @ryanair? This is bigoted rubbish. All South Africans speak Afrikaans?," and adding that Hendrik Verwoerd, the South African politician often dubbed the "architect" of the racist Apartheid regime, "would be proud of you."

"South Africa has 11 official languages," chided another user on the social network. "We are no longer in Apartheid, educate yourself."

Next week, on June 16, South Africa marks the national Youth Day holiday, which commemorates the 1976 student uprising when thousands of children took to the streets to protest Afrikaans being imposed as the singular, compulsory language of the country's education system.

Police met the protest with live ammunition and tear gas, killing more than 176 students.

South African officials have said they were taken aback by the airline's test in Afrikaans, calling it a "backward profiling system," according to the Reuters news agency. The country's Department of Home Affairs runs a 24-hour operations center that airlines can access to verify passports.

The 15 questions on the airline's nationality test include things like asking people to give the country's dialing code and naming its president, as well naming three of its official languages.

In its statement, Ryanair said if passengers "are unable to complete the questionnaire, they will be refused travel and issued with a full refund."