Ousmane Sonko, a leading opposition figure in Senegal, has been charged with new offences and his party dissolved.
The interior minister said Mr Sonko and his Pastef party had been calling for insurrection. The firebrand opposition leader is in custody.
His supporters believe all charges against him are politically motivated - to prevent him from standing in next year's elections, which the authorities have denied.
In June, he was at the centre of a controversial rape trial which saw him sentenced to two years in prison for "corrupting youth", meaning he was found to have acted immorally towards an individual younger than 21, after allegations made by a massage therapist. He was, however, acquitted of rape and making death threats.
That sentencing sparked violent protests in one of Africa's most stable nations which left at least 16 people dead and hundreds injured, according to officials.
However, he wasn't taken to prison but remained under house arrest, until Friday when he was arrested.
In order to forestall a repeat of such protests, Senegal has restricted access to the internet, as it did in June.
Who is Ousmane Sonko?
Despite the controversial rape trial, he is hugely popular among young Senegalese people who demand change amid a backdrop of economic hardship. His critics, however, accuse his movement of being a populist surge stoking division and tension.
Some say the 48-year-old tax inspector-turned-whistleblower is so popular because he has been electrifying young people with a slick social media campaign, which he uses to rip into Senegalese elites and whip up nationalist sentiment.
Using his youthful charm and digital connection with the youth, Mr Sonko drums up support by posing as a generational shift from Senegal's old political order.
A public law graduate, he rose from being dismissed as a tax inspector for speaking publicly about alleged tax evasion to become a member of the National Assembly, and then last year mayor of the southern city of Ziguinchor.
In and out of court since 2021, not much has been achieved during his tenure as mayor, but his supporters say he gives them hope and is an anti-corruption figurehead.
"He's anti-system," says step-dancer Pape Samba Ndour, a staunch supporter of Mr Sonko. "The system we got has been here since 1960. We want a new image of Senegal. He's against corruption."
Mr Sonko was the youngest candidate in the country's 2019 presidential election where he came third with about 16% of the vote. His fiery campaign speeches denouncing the government resonated favourably with many young Senegalese - and the country has a large youth population, with the average age in the country being 19, according to a government report.
The Patriots of Senegal (Pastef), the party he formed in 2014, has also gained political momentum.
Many young Senegalese frustrated by economic and social inequalities see the party as a viable alternative, in a country where nearly four in 10 live below the poverty line and about 22% of working age people are without a job.
"President Macky Sall didn't factor them [youths] into his political decisions," former Prime Minister Aminata Touré, a former close ally of Mr Sall but now one of his harshest critics, tells the BBC.
So Mr Sonko's promise to create jobs and grow the economy, which the World Bank says slowed down last year, has attracted followers.
But his detractors say he is a rabble-rouser who uses populism to win public sympathy.
Women's right groups also condemned Mr Sonko for making derogatory comments about the woman he was accused of raping during his trial, comparing her to a "monkey" who had had a stroke.
Others highlight his inflammatory language, such as in 2018, when he said that "those who have ruled Senegal deserve to be shot".
More recently, they say the rhetoric of his Pastef party, which called on citizens to "stop all activity and take to the streets" after he was sentenced, encouraged protests. He denies this.
French resentment
His criticism of Senegal elites' cosy relationship with France, the country's former colonial power, also strikes a chord among supporters.
France has been a target of embittered African complaints and criticism, especially among progressive French-speaking West African commentators and urban youths.
Although China overtook it in 2019, France is historically Senegal's largest source of foreign investment. Many French businesses such as supermarkets, petrol stations, mobile phone shops and other firms operate in Senegal, which some believe is harming the interests of local business owners.
It is common to see French-owned businesses being targeted during deadly protests like the ones last month. The slogan "France Dégage" (France Out) is also popular during demonstrations.
Before now a taboo subject in Senegal, Mr Sonko's call for a "responsible and intelligent" exit from the CFA franc - the regional currency used by 14 African countries and pegged to the euro under a French government guarantee - has increased his popularity.
While supporters say the CFA guarantees financial stability, critics say it is a way for France to continue to exercise control over the countries which use it.
For one, Mr Ndour, 27, supports Mr Sonko because he "is against" giving all of Senegal's resources to France.
Mr Sonko says he has "nothing against France, or against any other country".
But the centuries-old links between Senegal and France are "based on relations that are not completely rosy for Senegal", he told state-owned France Médias Monde.
Election in the balance
Pastef won 56 of Senegal's 165 parliamentary seats in the 2022 National Assembly election after forming an alliance with four other parties.
This achievement has emboldened Mr Sonko and led his supporters to believe he have a good shot at the presidency.
But Mr Sonko's name may be missing on the ballot in next February's polls because his conviction appears to threaten his eligibility, according to Senegal's electoral code. However he can ask for retrial.
But now that he faces trial on different charges, that looks more difficult.
For his supporters, this brings flashbacks of the convictions that barred two strong opposition candidates ahead of the 2019 presidential election.
Both Karim Wade, the son of former President Abdoulaye Wade, and Khalifa Sall, a former mayor of Dakar who is not related to President Sall, were jailed for graft and corruption in 2015 and 2018, respectively.
Critics say the government is using the judiciary to hound the opposition.
The government retorts that there is a separation of powers and accuses the opposition of stoking chaos.
Mr Ndour, who has been organising demonstrations online, hopes Mr Sonko and every other potential candidate are not barred from running for the presidency.
Much of the anger over Mr Sonko's arrest was fuelled by speculation that President Sall could run for a third term, which they argued was unconstitutional. He has since announced that he will not, which Mr Sonko's supporters see as victory.
However, that victory would feel empty if their man's name is also missing from the ballot paper.
Additional reporting by Hamet Fall Diagne and Gaïus Kowene.