Polls opened in Algeria on Sunday in a referendum on constitutional changes pushed by President Abdelmadjid Tebboune and the powerful military as a way to turn the page on last year's popular unrest.

The referendum is seen as a test of strength for both Tebboune and the leaderless opposition "Hirak" protest movement that brought thousands of people onto the streets weekly to demand radical change, and which rejects the vote.

Tebboune, who has been in hospital in Germany since last week after saying aides had tested positive for COVID-19, has pushed for a big turnout, which would demonstrate popular support for his strategy of moving on from the demonstrations.

In a statement late on Saturday to commemorate the anniversary of Algeria's war of independence from France, read out on his behalf because of his absence in Germany, he again urged people to vote.

However, there was little evident enthusiasm for the ballot on Sunday morning amid strict health measures because of the global pandemic.

"There is no point in voting. This constitution will not change anything," said 30-year old bus driver Hassan Rabia, sitting with two friends at a cafe in central Algiers.

At the Ali Chekir school at Ouled Fayet west of Algiers, about 10 people were waiting to vote. "Let's hope for the better and pray for Tebboune's speedy recovery," said Ahmed Slimane, 60.

Referencing Tebboune's hospitalisation in Germany, a cartoon in el Watan newspaper showed a man standing at a polling booth and sweating, looking at ballots marked 'yes' and 'no' in German rather than in Algeria's official languages of Arabic and French.

Tebboune has presented the changes as addressing - at least in part - the wishes of the protesters who last year forced his predecessor Abdelaziz Bouteflika to step down after 20 years in office.

However, their demands - replacing the ruling elite that has governed since independence in 1963, the military's withdrawal from politics and an end to corruption - have been at best only partly met.

Many of Bouteflika's closest allies and other top officials, including his brother Said and the former intelligence chief Mohamed Mediene, as well as major business tycoons, have been jailed on corruption charges.

The new constitution includes presidential term limits and more powers for the parliament and judiciary.

However, the military remains the most powerful institution in Algerian politics, though it has played a less prominent role since Tebboune's election.

The new constitution gives it a new power - the right to intervene outside Algeria's borders under certain conditions, with the generals concerned about insecurity in neighbouring Libya and Mali.