PRETORIA, South Africa (AP) — South Africa has apologized for a mass deportation of Nigerians, saying officials at Johannesburg’s main airport did not properly check their health certificates.

At a news conference in Pretoria Thursday, deputy foreign minister Ibrahim Ibrahim said: "We wish to humbly apologize to them, and we have."

Two diplomats from the Nigerian High Commission accompanied Ibrahim to the news conference, but refused to comment beyond a joint statement that described tit-for-tat deportations the two countries say should not affect their relations.

On March 2, South Africa deported 125 Nigerians who, according to airport health authorities, carried fraudulent yellow fever cards. Since then, authorities in Lagos have deported South Africans, raising health concerns.