Diplomatic tensions between Kenya and Tanzania have flared once again, this time over the treatment of Kenyan activists.

Former Chief Justice Willy Mutunga, human rights activists Hussein Khalid and Hanifa Adan were deported from Tanzania on Monday after being detained at the Julius Nyerere International Airport.

Simultaneously, activist Boniface Mwangi was arrested and held in Dar es Salaam, sparking outrage across the region. The trio had travelled to Tanzania to show solidarity with opposition politician Tundu Lissu, whose court case was scheduled for mention on Monday. However, shortly after arrival, they were blocked from entering the country.

President Samia Suluhu, in apparent reference to the deported Kenyans, said some foreign activist were meddling in Tanzanian affairs.

“Let them not come and mess things here. We should not give them any chance. They have already messed up their country. The only country remaining that is peaceful is Tanzania. I ask the security agencies not to allow foreigners to come and misbehave in Tanzania,” she said during an event to launch a new foreign policy held at the Julius Nyerere International Convention Centre.

Earlier, Mutunga, Khalid, and Adan had been detained without explanation in the airport’s interrogation room for several hours before being placed on a return flight to Nairobi.

“We’ve been detained at Julius Nyerere International Airport, and we’re not being told why,” said Hanifa in a post on X (formerly Twitter). “It’s 3 a.m. and freezing. I’m here with Willy Mutunga and Hussein Khalid. We came in solidarity with Tundu Lissu.”

The three were later informed they would be deported, a move that has drawn criticism from the civil society and the Kenyan government. Kenya’s Principal Secretary for Foreign Affairs Korir Sing’oei, called on Tanzania to uphold the principles of the East African Community.

“We strongly urge Tanzanian authorities to release the former Chief Justice of Kenya and his delegation, consistent with the norms of the East African Community,” Sing’oei said in a statement issued Sunday.

The situation escalated when Boniface Mwangi, who had also travelled to Tanzania in solidarity with Lissu, was arrested in Dar es Salaam.

Before the arrest, Mwangi had described a standoff at the Serena Hotel in Dar es Salaam, where armed men in civilian clothes surrounded his room. “They claim to be police officers but refused to identify themselves. I will not open the door. They’ll have to break it down,” he wrote on social media.

An hour later, Mwangi reported that the unidentified men had left his door and moved to the hotel lobby. “My bags are packed, and I’m ready to go once the Tanzanian lawyers arrive. For now, I’ll stay put. Thank you for the solidarity,” he posted.

The deportation of the three Kenyans came just hours after Tanzania also denied entry to Martha Karua, leader of Kenya’s People’s Liberation Party, and two other people. Like Mutunga and his team, they had also travelled to observe Lissu’s court proceedings.

Interestingly, another former Chief Justice, David Maraga, who succeeded Mutunga, was allowed to enter Tanzania without incident.

Maraga confirmed his arrival via social media: “Safely arrived in Dar es Salaam. Headed to Court for the Tundu Lissu case.”

Speaking during a press briefing at Harambee House on Monday, Government Spokesperson Isaac Mwaura acknowledged the deportations.

“It is true that Hon Martha Karua travelled to Tanzania in solidarity with Tundu Lissu. As East Africans, people have the right to visit other countries,” he said.

He added: “While we may not know the specific reasons for the denial of entry in this case, it does not mean that the principles of the East African Community or regional trade have been suspended. One incident does not halt our cooperation or economic engagement with Tanzania.”