The United States has expressed concern over the “mistreatment” of two East African activists in Tanzania, days after they were detained and reportedly tortured.

Human rights activists Boniface Mwangi of Kenya and Agather Atuhaire of Uganda travelled to Tanzania this week in solidarity with detained opposition leader Tundu Lissu ahead of his court hearing on charges of treason, which carries a potential death penalty.

But they were detained before being deported and then found abandoned near the Tanzanian border.

In a statement through its Bureau of African Affairs, the United States appealed to all countries in the region to hold those culpable to account. 

“The United States is deeply concerned by reports of the mistreatment in Tanzania of two East African activists – Ugandan activist Agather Atuhaire and Kenyan activist Boniface Mwangi.  Atuhaire was recognized by the US State Department in 2024 as an International Women of Courage Awardee,” the US Bureau said

“We call for an immediate and full investigation into the allegations of human rights abuses.  We urge all countries in the region to hold to account those responsible for violating human rights, including torture.”

Mwangi and Agather were arrested in Tanzania, where they had gone to show support for opposition leader Tundu Lissu during his court appearance on Monday.

The activists were held incommunicado for two days before resurfacing at various border points.

“I have gone through four very dark days, I have been tortured very badly, I can barely walk,” Mwangi stated shortly after he was found at the Kenya-Tanzania border in Horohoro. 

On her part, Agather, who was found at the Mutukula border between Tanzania and Uganda, narrated how the Tanzaniani authorities assaulted her.

“When I get there, the first order is to take off my clothes. Before I did anything, there was someone who hit me on my back and another who violently took off my clothes. They threw me down and handcuffed me. They tried to put a sweater so the injuries on my hands would have been quite severe,” Atuhaire stated.

Atuhaire received in 2023 the EU Human Rights Defender Award for her work in Uganda and was honoured last year with the International Women of Courage Award by former US First Lady Jill Biden.

Mwangi is a longtime critic of the Kenyan government, frequently denouncing instances of alleged injustice and rights abuses.