But Chadema accuses the security forces of being behind the disappearance of several members and the killing of Ali Mohamed Kibao, of its national secretariat, who was found dead earlier this month.

The party said Lissu had been arrested early Monday and police had also blocked access to the home of party chairman Freeman Mbowe.

Lissu, an opposition stalwart, has been arrested countless times and was shot in an assassination attempt in 2017.

He returned to Tanzania last year after Hassan lifted the ban on opposition rallies.

But he was arrested again in August, along with dozens of Chadema members, when the party tried to hold a youth day rally.

Rights groups and Western governments, including the United States, have criticised the crackdowns, which have raised fears of renewed repression ahead of local elections in November and a general election in late 2025.

“I remind Tanzanians that we are going to hold peaceful protests. We are neither carrying any weapons nor planning to violate the peace as some people allege,” party chairman Mbowe said in a speech broadcast on X on Sunday.

Riot police with water cannons were deployed from Saturday across key areas of Dar es Salaam.

“We have seen the deployment of armed police officers in the city but we are ready to face them. In case some of us will be arrested, hurt or even killed, pray for us and never turn back. We are doing this to make our country a peaceful place to live,” Mbowe said Sunday.

str-er/kjm

© Agence France-Presse