The head of Tanzania's main opposition party on Friday condemned what he described as a climate of fear installed by a "police state" after he was held in prison for more than three months.
Freeman Mbowe, head of the Chadema party, and fellow lawmaker Esther Matiko who was also jailed, described appalling prison conditions.
"This country has become a real police state," Mbowe told a press conference.
"Fear has gripped the country... people don't dare speak out, freedom of the press no longer exists," he said.
Mbowe and Matiko were arrested in November after they failed to appear in court twice to face charges over a protest march in February 2018 during which a 22-year-old student was killed by a police stray bullet.
In an appeal by the pair, judge Sam Rumanyika ruled last Thursday that their rights had been violated and ordered their immediate release on bail.
Critics say President John Magufuli has unleashed a wave of oppression since his election in 2015, cracking down on opposition figures, the media, and gay people.
"The death of the opposition would be a disaster for the country. You cannot build a democracy by beating or silencing your adversary," said Mbowe.
Mbowe said that in prison, some inmates spent up to two weeks without washing, which led to infectious diseases such as scabies, with prisoners scratching themselves "until blood flows".
He said prisoners are so tightly packed into cells that when sleeping, a "group leader" takes charge, clapping his hands so everyone can roll over in unison.
Meanwhile in the women's prison, Matiko said the mentally ill were locked up with criminal offenders. He vowed to take up the issue in parliament.