Two more Nigerians have been reported dead in South Africa in the wake of tensions over African migrants in the former apartheid country.

Kimiebi Ebienfa, foreign ministry spokesperson, identified the deceased Nigerians as Emeka Charles Iroegbu and Musa Yunana Joe. Both citizens were killed on the same day in separate incidents.

In a statement on Sunday, Ebienfa said Iroegbu was reportedly killed by Tshwane Metro police officers who used gruesome interrogation techniques on the Nigerian. The incident happened on June 28 in Sunnyside, Pretoria.

According to the statement, the same officers were allegedly responsible for the extra-judicial killing of another Nigerian identified as Nnaemeka Mathew Andrew Ekpenyong whose case is still pending.

“No arrests have been made, even though the four officers involved are known to the South African Police Service (SAPS),” Ebienfa said.

Joe, the second citizen, popularly known as Big Joe, was reportedly killed in front of his shop on in Witbank, Mpumalanga. His killers have yet to be identified.

In April, when the xenophobic violence in South Africa began to rise, the Nigerian Consulate in Johannesburg said two Nigerians were killed.