President Abdelaziz Bouteflika stepped down after 20 years in power this month, bowing to pressure from the army and weeks of demonstrations mainly by young people seeking change.
“The system must go” and “We are fed up with you,” read banners held up by protesters in central Algiers.
The protests, which began on Feb. 22 and have been largely peaceful, have continued as many want the removal of an elite that has governed Algeria since independence from France in 1962 and the prosecution of people they see as corrupt.
Bouteflika has been replaced by Abdelkader Bensalah, head of the upper house of parliament, as interim president for 90 days until a presidential election on July 4.
Algeria’s wealthiest businessman and four other billionaires close to Bouteflika were arrested this week as part of an anti-graft investigation, state media said.
Algeria’s army chief Lieutenant-General Ahmed Gaed Salah has said he expected members of the ruling elite to be prosecuted for corruption.
Salah intervened when Bouteflika sought to extend his fourth term, declaring him unfit for office in a bid to avoid prolonged turmoil.