Tens of thousands in Algeria have taken to the streets angry at 81-year-old President Abdelaziz Bouteflika’s plan to seek a fifth term in office.
Police fired tear gas at protesters in the capital, Algiers.
According to authorities seven protesters and more than 50 officers were injured, with 45 people arrested.
Anti-government protests are rare in Algeria but several broke out after Mr Bouteflika confirmed his candidacy.
He has rarely been seen in public since suffering a stroke in 2013 and is currently undergoing medical checks in Switzerland.
As they marched through the streets of Algiers on Friday, some demonstrators carried banners saying “leave means leave”. Others stressed their intentions were peaceful.
“Twenty years are enough,” said one woman, quoted by AFP news agency, who was joined by her husband and children.
“This is a celebration, not a protest,” Ali Selmi told Reuters news agency. “We are celebrating Algeria’s rebirth.”
Some protesters threw stones near the presidential palace and were driven back by police firing tear gas. Witnesses said there were injuries on both sides.
Demonstrations also took place following Friday prayers in several other cities in Algeria.
Mr Bouteflika came to power in 1999 and is credited with putting an end to a civil war that is estimated to have killed more than 100,000 people.
Protests against food prices and unemployment broke out in 2011 during the Arab Spring but he responded by lifting a nearly two-decades old state of emergency, meeting a key demand of protesters.
After his stroke he won re-election in a poll denounced by the opposition and dissolved the country’s powerful spy agency, replacing it with a body loyal to him.
Critics say his ill health means that he is unable to perform his duties as president.
Despite the show of dissent, Mr Bouteflika is still widely tipped to win the election in April.