Hundreds of thousands of people protested in central Algiers on Friday in the biggest demonstration against President Abdelaziz Bouteflika's 20-year rule since unrest began last month.

Protesters crammed streets and squares in the capital after Friday prayers, many draped in Algeria's red, green and white flag. Demonstrations also took place in Bejaia, Oran, Batna, Tizi Ouzou and other cities.

"Bouteflika and his men must go as soon as possible," said student Yazid Ammari, 23.

Bouteflika on Monday reversed a decision to stand for another term after weeks of demonstrations against him but he stopped short of relinquishing office and said he would stay on until a new constitution is adopted.

Algerians quickly rejected his offer and demanded that the 82-year-old president hand over power to a young generation of leaders who can create jobs and stamp out corruption

"Those who think we are tired are wrong. Our protests will not stop," said doctor Madjid Benzida, 37, as police blocked streets leading to government offices and parliament.

Bouteflika has been losing allies in recent days since returning from medical treatment in Switzerland.