Tens of thousands gathered across Algeria on Friday in large demonstrations against the country’s ailing octogenarian President Abdelaziz Bouteflika who is seeking a fifth term in office.
After scuffles with police who used teargas to disperse the crowds, security forces said they had arrested 41 people.
"No to Bouteflika and no to Said," a crowd chanted while marching through the centre of Algiers. The president's youngest brother Said Bouteflika is a presidential adviser.
Publicised on social media, the demonstrations went ahead despite mosque preachers warning of possible violence.
"We and the security [forces] are brothers," some protesters called in the capital.
Police attempted to prevent protesters from reaching the presidential palace, prompting some demonstrators to respond by throwing rocks.
The Directorate General for National Security, said Saturday it had detained 41 people over "public disorder, vandalism, damage to property, violence and assault".
Despite the arrests, protests around the country were largely tolerated by authorities, even in the capital, where demonstrations have been strictly banned since 2001.
Protests were held in at least five other cities, including Oran, Tizi Ouzou, Bejaia, Annaba and Setif, news website TSA said, citing witnesses and posting videos.
The police did not give an estimate of the number of protesters, but a security official speaking on condition of anonymity said that around 20,000 people had demonstrated nationwide, around a quarter of them in Algiers.
The official said 38 of the arrests were in the capital, and that no security personnel had been wounded.
Activists had used social media to call for nationwide protests against Mr Bouteflika on Friday after weekly Muslim prayers.
The 81-year-old, who uses a wheelchair and has rarely been seen in public since suffering a stroke in 2013, announced on February 10 that he will run for another term in an April presidential election.
Mr Bouteflika’s re-election bid comes after the ruling FLN party picked him as its official presidential candidate. Several political parties, trade unions and business organisations have already said they would back him, and he is expected to win easily as the opposition remains weak and divided.
His re-election would provide short-term stability for the FLN, the army and business tycoons, and postpone a potentially difficult succession.
Strikes and protests over social and economic grievances are frequent in Algeria, but are generally localised and do not touch on national politics.
Known for wearing a three-piece suit even in the stifling heat, Mr Bouteflika garnered respect for his role in ending Algeria’s decades-long civil war that official figures say killed nearly 200,000 people.
But 20 years later, much of the country – 40 per cent of Algeria's 42 million-strong population are under the age of 25 – have never known another leader.
While he might be respected, may point to poor employment figures as evidence he has not done enough to utilise the country’s abundant resources to build the economy.
As well as large amounts of oil and gas, the country has large reserves of phosphates and uranium. However, the country is grappling with high corruption and poor investment.
An oil boom between 2004 and 2014 allowed Mr Boutaflika to launch vast infrastructure programmes and offer generous subsidies to help pull the country out of debt. But the system is now creaking under the weight of its ballooning share of the government budget – now around 21 per cent of all official spending.
The government shelved plans to reform the subsidy program late last year until after the presidential election, citing the risk of protests in the run up the vote.
The country's hydrocarbon-dependent economy was hit hard by a drop in crude prices during the president's fourth term, and now nearly a third of Algerians under 25 are unemployed.
Mr Bouteflika has also faced criticism from rights groups and opponents who accuse him of being authoritarian.
The president’s office said late on Thursday that he would travel to Switzerland on Sunday for "routine medical checks", without giving further details. He has travelled before to Geneva for medical tests.