N'Djamena (AFP) - "Fear rules over the city," said Mahamat, a resident of the Chadian capital N'Djamena for more than 40 years who did not dare to reveal his real name.
"Although people are frustrated, they don't want to be arrested, kidnapped or tortured."
In Chad, a large partly-desert nation straddling north and central Africa, taking discontent to the streets is a dangerous game under the stern rule of President Idriss Deby, in power for 27 years.
Early in January, a public sector strike over pay and conditions garnered some backing, but once trade unions, students and the political opposition urged people to demonstrate against "bad governance", security forces were deployed across the capital and few chose to protest.
The regime, which is fighting the violent jihadist group Boko Haram based in neighbouring Nigeria but active across several borders, argues that the risk of attack is too high to allow marches and public gatherings.
"Terrorists, thugs, could infiltrate the march," Security Minister Ahmat Bachir recently warned.
Among those who have risked public protest, several hundred people have been arrested since the end of January.
Most were released after spending several hours in custody, but police on Wednesday said 17 people were sentenced to four months in prison for "disturbing public order, destruction of property, holding an unauthorised gathering and injuring members of the police force".
The prosecutor of Chad, Mahamat Saleh, warned protesters: "There will be zero tolerance for troublemakers."
Last week, the authorities also handed down two month suspensions to ten opposition parties that called for a protest rally in N'Djamena on the grounds that they were "disturbing public order" and "inciting violence".
- 'Illegal' arrests -
In a report released last September, Amnesty international charged that since early 2016, the security forces have stepped up "efforts to repress human rights", with a key role for the feared national intelligence agency (ANS).
The report said the ANS's mandate was expanded in January 2017 "allowing its agents to target and arrest human rights defenders on the grounds of national security".
"The ANS had already been illegally arresting people and detaining them in unofficial detention facilities, without allowing access to families and lawyers," Amnesty reported.
Secret detention and arbitrary arrests marked a return to a dark past, said the human rights NGO, referring to the brutal methods of the infamous Directorate for Documentation and Security under former president Hissene Habre, who was ousted by Deby and sentenced by a special court in Dakar in 2016 to life in jail for crimes against humanity.
"For the past two weeks, we've seen what happened under Habre," including "arrests in bedrooms", Clement Abaifouta, chairman of an organisation representing Habre's many victims, told AFP.
The presence of security forces and suspected government "spies" around N'Djamena has helped fuel rumours that opposition groups are being infiltrated. "We are wary of each other," said a human rights activist who wished to remain anonymous.
Yet in spite of the oppressive climate, Chad has in the past three years witnessed "an increase in strength of social movements and popular protests that breaks with the political opposition and armed rebel groups," observes Chadian sociologist Appolinaire Rititingar.
- 'It's all going to blow' -
With a movement called "Lyina" ("That's Enough"), young Chadians have picked up the example of youths in Senegal and Burkina Faso and their "Fed Up" and "Citizens' Broom" campaigns.
These two movements played a decisive role in the politics of their respective countries to bring down the unpopular presidents Abdoulaye Wade and Blaise Compaore.
But in Chad, apart from repression, "we lack unity in our protests and in calls to demonstrate, for many of our leaders go solo," said a representative of civil society who asked not to be named.
Moreover, political scientist Evariste Ngarlem Tolde at the University of N'Djamena argues that "Chadian civil society has no social roots, since it has not worked on raising awareness as in other countries."
"People often don't even understand the why of what civil society does," Rititingar said, pointing out that almost half of Chad's population of some 13.6 million live beneath the poverty line and survive "hand to mouth".
"One day, it's all going to blow at once," said a city resident using the name Abakar, looking both fearful and joyous.
Chad introduced new austerity measures in January to meet the requirements of international donors in a bid to escape from a latent crisis that has undermined the economy for years.
General discontent with Deby's regime now crosses ethnic divides, according to Ngarlem Tolde, who notes that social movements in Chad tend to emerge spontaneously.
In February 2016, the revelation that a 17-year-old girl had been gang raped by youths close to the family of the head of state triggered widespread protests that lasted several months.