Three Tunisians jailed for 30 years for cannabis use
Mohamed Faouzi Daoudi, a spokesman for the court in Kef in northern Tunisia, told AFP on Sunday that the decision was "not just about drug use, but also the use of a sports field for their consumption."
He said Tunisian law reserved harsh penalties for drug use in public spaces, and cited "law 52".
The January 20 ruling can be appealed.
Amna Guellali, from campaign group Amnesty International, said such sentences for drug use and possession were "unacceptable on principle".
She said they were "a means of dissuasion that targets young people", harming the youth but without introducing reforms that could help.
The Tunisian League of Human Rights called the verdict "unjust".
Nour Khammassi, an official from the group's Kef branch, said law 52 should be revised.
Social media users also denounced the court decision and called for demonstrations and changes to the law.
Academic Raja Ben Slama was among those who slammed the verdict on Facebook, calling it "absurd and contrary to human rights, the constitution, conventions and everything humane".