DAKAR, Senegal (AP) — Six people who were deported by the United States to Liberia last week resisted getting off the plane and instead were sent to Equatorial Guinea, another ‌African nation that signed a third-country deportation agreement with the Trump administration, a person on the plane and a lawyer in contact with the six said Monday.

Under a series of often secret agreements, the Trump administration has deported thousands of people to two dozen countries that aren’t their own as it pushes ahead with its immigration crackdown, advocates say.

Immigration lawyers say the practice is being used as a legal loophole to indirectly return some asylum seekers to countries they fled.