African leaders have called on the Israeli government to release their citizens who were part of hundreds of activists on the Global Sumud Flotilla carrying humanitarian supplies to the Palestinian city of Gaza. The flotilla, comprising about 40 boats, was intercepted on Wednesday after weeks of sailing.

Among those detained is the grandson of former South African President Nelson Mandela, Nkosi Zwelivelile Mandela. President Cyril Ramaphosa described the detention of the activists as a violation of international law: “On behalf of our government and nation, I call on Israel to immediately release the South Africans abducted in international waters, and to release other nationals who have tried to reach Gaza with humanitarian aid.”

President Kais Saied of Tunisia said “intensive diplomatic efforts have been ongoing for days without interruption” to secure the release of Tunisians detained, noting that his country remains “steadfast and unwavering in its principled positions.”