South Africa is asking several other African governments to reimburse it for the cost of sending tens of thousands of their citizens back home.

The country has spent nearly $18 million accommodating and transporting migrants who returned or were deported following heightened tensions and protests over illegal immigration, the Home Affairs Department told lawmakers on Tuesday.

Officials said the Foreign Ministry has formally asked Malawi, Ethiopia and Nigeria to reimburse some of the costs.

The expenses included transportation, temporary repatriation centers and staff overtime. Home Affairs Director-General Tommy Makhode described the costs as "unforeseen and unavoidable."

Some municipalities and government departments involved in the repatriation process are also seeking compensation from the Home Affairs Department, saying the expenses were not included in their budgets.

Home Affairs Minister Leon Schreiber has described the recent scale of deportations and repatriations as unprecedented.

The departures come amid growing tensions over immigration in South Africa, where anti-illegal migration groups have staged protests and attacks on foreign nationals have strained relations with other African countries. The groups have blamed migrants for unemployment, crime and pressure on public services.

Several governments have accused South Africa of failing to protect their citizens, allegations Pretoria has rejected.

Ghana recently sought to have the situation included on the agenda of an upcoming African Union meeting, but the proposal was rejected by the continental body.

South African government figures show that 82,875 people have either been voluntarily repatriated or deported since the latest migration tensions began. However, figures from migrants' home governments put the number at around 178,000.

The repatriations form part of wider government efforts to curb illegal immigration. Between April and July, 16,078 people, mainly from Lesotho, Malawi, Tanzania, Zimbabwe and Mozambique, were deported through the Lindela Repatriation Center.

South African law enforcement officials said last week that operations targeting illegal immigration and related offences would be intensified.

Authorities said they had arrested nearly 60,000 people living in the country illegally, including 16,208 arrests in July alone.