Anti-government protesters thronged the streets of Algeria's capital and other cities on Friday, saying moves by top loyalists to abandon ailing President Abdelaziz Bouteflika were not enough.

While there were no official figures, security sources said hundreds of thousands turned out in Algiers and that marches were held in at least 36 of the North African country's 48 provinces.

For a sixth successive Friday, the huge numbers turned out despite a string of loyalists deserting the president and calling for him to step down and make way for a government-led change of leadership. 

Activists clash with riot police in Algiers. Photo: AFP

Activists angrily rejected those moves as desperate bids by key figures in Bouteflika's entourage to salvage their own grip on power and demanded that they too quit.

"Bouteflika you go, take Gaid Salah with you," and "FLN out" protesters in the capital shouted, referring to the armed forces chief of staff and the president's party.

Crowds of demonstrators, many of them young but also including army veterans of Algeria's 1990s civil war, packed the square outside the main post office, which has become the epicentre of protests.

"We're fed up with those in power," the demonstrators chanted. "We want a new government".

Some waved the green, white and red Algerian flag or draped it over their shoulders, while others held banners with slogans and cartoons.

Some made lengthy journeys to take part in the protest.

"We're here to issue a final appeal to those in power: 'Take your bags and go'," said Amin, a 45-year-old who travelled to the capital from the port of Bejaia, nearly 200 kilometres (125 miles) away.

Earlier this month, 82-year-old Bouteflika, who uses a wheelchair and has rarely been seen in public since suffering a stroke in 2013, said he would not stand for re-election -- but also postponed the April vote.

His move angered Algerians who saw it as a ploy by those around him to extend his two decades in power. Tens of thousands again took to the streets demanding his immediate ouster.

Allies distance themselves 

Faced with persistent public anger, a succession of veteran Bouteflika loyalists deserted the president this week. 

Bouteflika has promised not to run again - but that has not placated protesters. Photo: AFP

On Tuesday, chief of staff General Ahmed Gaid Salah, who was appointed by Bouteflika in 2004, called for him to step down or be declared medically unfit.

The chief of staff cited Article 102 of the constitution, under which a president can be removed if found unfit to rule.

Long a faithful Bouteflika supporter, Gaid Salah said on television it was "imperative" to find a way out of the crisis "which responds to the legitimate demands" of the people in line with the constitution.

Article 102 puts the onus on the president either to resign or be declared unfit to govern by a vote of parliament due to a "serious and durable illness".

Since then, other voices have emerged from Bouteflika's own camp seeking his ouster.

On Wednesday, Bouteflika's longtime coalition partner, the National Rally for Democracy (RND) of former prime minister Ahmed Ouyahia, also called for him to step down.

Huge crowds filled the streets of Algiers. Photo: AFP

The RND said it "recommends the resignation of the president... with the aim of smoothing the period of transition," in a statement signed by its leader Ouyahia.

A longtime supporter of the veteran president, the unpopular Ouyahia served as Bouteflika's prime minister three times since 2003 before being sacrificed on March 11 in a vain bid to calm the intensifying protests.

'All of you go' 

The head of the powerful General Union of Algerian Workers (UGTA), Abdelmadjid Sidi Said, also welcomed the army chief's call on Wednesday.

Applying Article 102 would constitute "the legal framework capable of overcoming the political crisis facing our country," he said.

Thursday saw the resignation of the president of Algeria's Business Leaders Forum, Ali Hadad, widely seen as a political tool of Bouteflika who had come under harsh criticism from protesters.

But the idea of Bouteflika's inner circle retaining their grip on power through a substitute leader drew short shrift from Friday's protesters.

Some chose humour to convey their rejection of the call for a government-led transition under Article 102.

"102 -- that number is out of service," said one placard held up by the crowd outside the main post office and telephone exchange. "Please call the people."

Others raised a banner saying: "We demand the implementation of Article 2019: All of you go."