A Saudi court has sentenced a retired teacher to death over his comments online, say his brother and advocacy group Human Rights Watch.

Muhammad al-Ghamdi, a 54-year-old retired Saudi teacher, was sentenced "following 5 tweets criticizing corruption and human rights violations," his brother Saeed bin Nasser al-Ghamdi tweeted last week.

According to Human Rights Watch, Muhammad al-Ghamdi was arrested last year and given little access to a lawyer before his conviction in July "under article 30 of Saudi Arabia's counterterrorism law for 'describing the King or the Crown Prince in a way that undermines religion or justice,' article 34 for 'supporting a terrorist ideology,' article 43 for 'communication with a terrorist entity,' and article 44 for publishing false news 'with the intention of executing a terrorist crime.'"

"Repression in Saudi Arabia has reached a terrifying new stage when a court can hand down the death penalty for nothing more than peaceful tweets," Joey Shea, Saudi Arabia researcher at Human Rights Watch, said in a Tuesday statement.

According to the European Saudi Organization for Human Rights, Saudi Arabia has executed at least 92 people this year so far. In 2022, UK-based human rights organization ALQST cataloged 148 executions in Saudi Arabia -- more than twice the number of executions it recorded in 2021.

The death sentence comes amid an "escalating crackdown" on free speech in the country, said Lina Alhathloul, ALQST head of monitoring and advocacy and sister of released Saudi political prisoner Loujain al-Hathloul.

"They are sending a clear and sinister message -- that nobody is safe, and even a tweet can get you killed," she said.

Al-Ghamdi's brother Saeed, a well-known Saudi Islamic scholar and government critic living in self-imposed exile in the United Kingdom, said he believe the severity of the sentence is designed to punish him as well.

"The Saudi authorities asked me several times to return to Saudi Arabia, but I refused to do so. It is very probable that this death sentence against my brother is in retaliation for my activity. Otherwise, his charges wouldn't have carried such a severe penalty," he said.

CNN reached out to Saudi Arabia's Ministry of Justice and Ministry of Interior for comment but had not received a response at the time of publication.