Tunisian security forces must refrain from using excessive force and end their use of intimidation tactics against peaceful demonstrators, Amnesty International said ahead of major anti-austerity protests planned across the country on Friday.

During the past four days of anti-government demonstrations, security forces have used increasingly heavy-handed methods to disperse rallies and subsequently arrest protesters. One protester has died during the unrest.

“The Tunisian authorities must prioritize the safety of peaceful protesters and ensure that security forces only use force where absolutely necessary and proportionate, and to protect the rights of others,” said Heba Morayef, Amnesty International’s Regional Director for the Middle East and North Africa.

“These protests are happening in response to genuine economic hardship, and the role of the police should be to calm this tense situation, rather than to inflame it.”

Tunisians have taken to the streets since Monday 8 January in more than 20 towns and cities across the country to protest against steep price rises and tax increases in a budget imposed by the country’s government.

The youth-led activist group“Fesh Nestannew?” (What are we waiting for?) called for mobilization to pressure the government to revise its plans, with demonstrations set to escalate on Friday after a call for mass rallies.

When a group of the movement’s members marched peacefully in downtown Tunis to demand the release of activists in custody on 8 January, security forces used batons to disperse them.

Police have arrested at least 15 of the group’s activists and coordinators for offences such as writing slogans on walls and distributing pamphlets calling for demonstrations. Many have subsequently been released after prolonged questioning.

One of those who remains detained is activist and philosophy professor Ahmed Sassi, who was arbitrarily arrested from his home in Tunis on Wednesday and will appear before a prosecutor on Friday.

“These arrests appear to be intimidation. The Tunisian authorities are targeting people for peacefully exercising their right to freedom of expression and assembly,” said Heba Morayef.

While several of the protests have been entirely peaceful, in some cases they have escalated into sporadic acts of violence where looting and vandalism occurred.

“Acts of vandalism and looting require a response from the security forces, but it must be proportionate to the crimes committed. Unrest on Tunisia’s streets must not give the police a green light to retaliate with the unlawful or excessive use of force,” said Heba Morayef.

Protester Khomsi el-Yerfeni died on Monday night during a demonstration in the town of Tebourba, 30km west of Tunis.

Eyewitnesses told Amnesty International he died after a police car ran him over twice. However, Tunisia’s Ministry of Interior said in a statement that he had suffocated to death from tear gas because he had a chronic respiratory condition.

Khomsi el-Yerfeni’s family has denied that he had any such chronic condition and told Amnesty International he never had any medical records in the hospital as claimed by the Ministry of the Interior.

The results of Khomsi el-Yerfeni’s autopsy have not yet been announced. In any case, if the police do use force to disperse a gathering, including by using tear gas, they must ensure that assistance and medical aid are given to any injured or affected persons at the earliest possible moment.

“The Tunisian authorities must immediately launch a thorough and impartial investigation into the death of Khomsi el-Yerfeni, including publishing the results of his autopsy in full transparency,” said Heba Morayef.

“If any law enforcement officers are found to be criminally responsible for his death, they must be brought to justice.”

According to international standards, police may only use force when strictly necessary and proportionate, and in a manner designed to minimize damage or injury.