Tanzania Human Rights Defenders Coalition (THRDC) has condemned the arrest and detention of Martha Karua, Gloria Kimani and Lynn Ngugi at Julius Nyerere International Airport, calling it an unlawful act that violates regional and international human rights standards.

The three were detained on Sunday morning upon arrival in Dar es Salaam.

They had travelled to Tanzania to observe treason proceedings against opposition leader Tundu Lissu, under the invitation of the East Africa Law Society in partnership with the Law Society of Kenya and the Uganda Law Society.

Karua, the People's Liberation Party leader and former presidential candidate, said immigration officials referred her passport to a supervisor, who then consulted senior authorities before informing her that entry had been denied without explanation. "The supervisor has now informed us that our entry into Tanzania has been denied, no reasons given," said Karua on her X page.