NAIROBI, Kenya — Police arrested Tanzania’s most prominent opposition figures Monday whose party has called for protests against what it says is a crackdown targeting its supporters.

Hundreds of backers of the country’s main opposition party, CHADEMA, were arrested last month and the party’s secretariat member Ali Kibao was abducted and later found dead with signs of beatings and acid poured on his face.

Amnesty International at the time called for an immediate stop to “arbitrary detentions of political opposition” in Tanzania.

Authorities said Monday’s arrests were made as party officials defied a prohibition on protests.

CHADEMA said in a statement its chairman Freeman Mbowe and his deputy Tundu Lissu together with six other party officials were arrested at various locations, adding that the planned protests were in line with the constitution and that police had been notified as required by law.

Mbowe and Lissu were arrested in August and later released.

President Samia Suluhu Hassan, who is serving out the late President John Magufuli’s term after he died in office in 2021, including the unbanning of rallies, but the recent killing of Kibao, which she was quick to condemn, sparked outrage.

Magufuli’s autocratic rule was marred by human rights abuse allegations that included a total ban on opposition political rallies.

Tanzania is set to hold a general election in 2025.