LAGOS, Nigeria — Nigeria said Sunday that two of its nationals were killed last month in South Africa following violent anti-immigrant protests targeting African workers in the country.

The Nigerians were killed June 28, two days before an unofficial deadline by protesters for foreigners to leave, the Nigerian Ministry of Foreign Affairs said. One was allegedly killed by police officers and the other by unidentified attackers, it said.

South African police did not immediately respond to a request for comment from The Associated Press.

Anti-immigrant protesters in April and May blamed foreigners for high levels of unemployment, crime and pressure on public services. The violence at the protests and attacks on Africans prompted Nigeria, Ghana and Malawi to repatriate their citizens and summon South African diplomats.

“These two killings come at a time when foreigners are being unduly targeted in South Africa. This raises questions about deliberate attempt by some elements to wrongfully generalise and tag well-meaning, hard-working, and respectable Nigerians as criminals,” Nigerian Foreign Ministry spokesperson Kimiebi Imomotimi Ebienfa said.

South Africa has a history of violence sparked by anger over the presence of migrants, including in 2008, when more than 60 people were killed in what international rights groups called xenophobic attacks on foreigners.