Hundreds of leaders and supporters of the Chadema party had been arrested ahead of a planned youth day rally. Dissidents voiced concerns about a return to the repressive policies of President Hassan's predecessor.

Most leaders of Chadema have been released as of Tuesday, officials said, a day after some 520 people connected to Tanzania's main opposition party were arrested.

In a post on social media site X, Chadema spokesman John Hrema said that party chairman Freeman Mbowe and his deputy Tundu Lissu "have been returned to Dar es Salaam by police and have bailed themselves out."

Police chief of operations Awadh Haji said "all the top Chadema leaders who were arrested, after interrogation and other procedures, have been returned to where they came from."

Chadema disputed that all of its officials had been released, but did not give any names.

The arrests came as young supporters of the party gathered for a rally meant to honor International Youth Day.

Fears of return to repression

Rights groups and dissidents have voiced concerns that the mass arrests signal a return to the repressive politics of the late president John Magufuli ahead of national elections next year.

Magufuli's former vice president and successor Samia Suluhu Hassan had promised a return to "competitive politics" upon taking office, and in 2023 she lifted a six-year ban on opposition gatherings. She has also eased restrictions on freedom of the press implemented under her predecessor. However, Chadema leader Mbowe has still expressed significant distrust of her administration.

es/nm (AFP, epd)