ALGIERS — Anti-riot police officers clash with people protesting against president Abdelaziz Bouteflika in Algiers. Photograph: Zohra Bensemra/Reuters

Police have fired teargas to disperse tens of thousands of demonstrators marching through central Algiers against Abdelaziz Bouteflika’s bid for a fifth term in office, the biggest protest in the Algerian capital since the Arab spring.

Other marches in cities around the country including Oran, Constantine, Sétif, Tizi Ouzou and Bouïra drew thousands more angry at the ailing president’s attempt to prolong his 20 years in power, local media reported.

Riot police fired teargas to disperse a group of around 200 young people, around 1.5km from the presidential palace in Algiers.

According to a police toll, 56 police and seven demonstrators were hurt and 45 arrests made in the capital. Witnesses reported a number of people wounded after being hit by batons, tear gas grenades and stones thrown by police back at demonstrators who had initially hurled them at officers.

Gathering in the capital after Friday prayers, protesters, some carrying roses, chanted “bye bye Bouteflika”, “peaceful, peaceful” and “the people reject Bouteflika and Saïd”, a reference to the 81-year-old president’s brother who is widely believed to be ruling in his name.

“The people want the fall of the regime,” some of those looking to converge at the Place de la Grande Poste in the city centre shouted, in an echo of the Arab spring protests that swept parts of north Africa eight years ago. Police helicopters circled overhead.

“There’s a huge crowd,” said Saïdani Meriem from the opposition party Jil Jadid, sharing photos of streets filled with protesters waving Algerian flags as they marched down the Rue Hassiba Ben Bouali in Algiers, where protests have officially been banned since 2001.

“It’s definitely a historic day,” Meriem said. “The president needs to respond to this mass movement, by first and foremost stopping his power grab.”

Hamdane Salim, a 45-year-old public sector worker, said Algeria’s youth was “demanding a valid president who can talk to the people”.

Nahla Djabi, another marcher, said the protesters were heading “towards the central post office, and from there the presidential palace. The atmosphere is very relaxed, there are plenty of families, women, children. It’s calm for the moment. It’s very joyous. We have hope, a lot of hope.”

Chloe Teevan, a Maghreb specialist at the European Council for Foreign Relations, said many people had taken to the streets even before the end of prayers. “There appear to be tens of thousands. There have been reports of police blocks and some use of teargas, but by and large the protests are proceeding peacefully,” she said.

Bouteflika’s opponents say the president, who has been seen in public only a handful of times since he suffered a serious stroke in 2013, is no longer fit to lead and that Algeria is being run by a group of advisers, including Saïd.

Protesters clash with police in the streets of Algiers on Friday. — Agencies