A woman being held in prison in Somalia for taking part in peaceful protests has described how she was tortured by her guards.

Sadia Moalim Ali, 27, told the Guardian she was stripped naked by two male guards in a room monitored by CCTV, kicked, beaten with a baton and left for two days in a small cell without food.

In an exclusive interview from prison, she said: “I was tortured. I was forced to lie face down on the ground, and water was poured on me. I was kicked by guards with boots on. They stood over me and beat me with a baton.

“I was taken into solitary confinement and kept there for two days. I was deprived of food and basic necessities while I was locked in that cell. I wasn’t allowed to leave to go to the toilet.”

Torture – defined as any act by which severe pain or suffering, physical or mental, is intentionally inflicted – is prohibited under international law and by the UN Convention against Torture in all circumstances.

Ali, a nursing graduate who works as a rickshaw driver, was arrested and detained in a police station on 12 April for her anti-government activism. She used Facebook and TikTok to criticise the federal government, speaking out against alleged corruption and nepotism, forced evictions, youth unemployment, taxation and high fuel prices.

On 14 April, she was transferred to Mogadishu central prison, where she remains. She said she had not been formally charged and had been denied access to a lawyer appointed for her. While in police detention, she said, she was pressed into signing a document she did not understand, and then taken to court.

According to Amnesty International, the police have been granted permission from the court to hold her for 90 days pending further investigation.

In an interview from prison that was aired on Shabelle Media, a Somali radio and television news organisation, on 20 April, Ali said she was being held without due legal process and appealed for her freedom.

It was because of that interview that she was tortured, she said. “Before when I spoke to the media, I was punished the same day … Truly a lot of pain was inflicted on me.”

The room she was kept in is known as cellula della morte – cell of death – named so because the prison was built during Italian rule, which ended in 1941. Former prisoners who have spent time in it say it is reserved to punish people and for those facing execution. The floor is said to be doused in engine oil and salt, and covered in faeces. It measures about two square metres and is extremely hot. The stench is overwhelming and has caused people to vomit.

Ali, the main breadwinner for her extended family including her 11-month-old daughter, now shares another cell with 38 other women.

“It is a very difficult life,” she said. “No human being deserves to be put in here. It is a place with no ventilation. Even a healthy person gets sick. It is very noisy and very crowded.”

She said she struggled to sleep and had kidney problems as well as numbness in her hand and foot, and just wanted to go home to her family, saying she would end her activism.

“I have endured severe violations and I deeply plead for justice, for my rights and my freedom to be restored by those responsible.”

Dalmar Dhayow, of the Coalition of Somali Human Rights Defenders, said women imprisoned in the country routinely faced a litany of human rights violations.

“We know sexual assault or violence is systematically used as a tool to force women [to make false confessions], humiliate and harass them inside prison,” said Dhayow. “We know a lot of cases of women being shackled while they are detained, with their legs and hands bound.”

Human rights organisations, former government officials and a Somali MP have said Ali’s detention is unlawful and are calling for her immediate release. Abdirahman Abdishakur, the leader of an opposition party, posted on X that Ali’s detention was “a national disgrace and a damning indictment of President Hassan Sheikh’s administration”.

“Her only ‘offence’ was speaking out against corruption and nepotism within government institutions,” he wrote. “That is not a crime; it is a fundamental civic right. Mr President, failing to tolerate the voice of a single young woman is not a sign of strength, it is a clear display of insecurity.”

Since 2022, Somali authorities have been accused of engaging in a systematic and escalating crackdown on human rights, using arbitrary arrests, detention, harassment, threats and intimidation to silence journalists, activists and other people who express dissenting views.

The Somali government was approached for comment but did not respond.