Public transport has been suspended in the Algerian capital, Algiers, ahead of another day of protests against plans by President Abdelaziz Bouteflika to seek a fifth term in office.

Mass demonstrations now entering their third week have posed the biggest challenge to the ailing 82-year-old president, who has ruled for 20 years and is standing for re-election on April 18.

Mass protests are expected to start in the afternoon.

Trains, buses and metros are affected. Since they began two weeks ago, the demonstrations across the country have been peaceful.

But the president has warned that unnamed domestic or foreign groups might infiltrate the protests and plunge Algeria into chaos.

Mr Bouteflika – who’s been in power for 20 years – has rarely appeared in public since he suffered a stroke in 2013. He’s currently in hospital in Switzerland.

Algerians have been urged to stage a “March of 20 Million” by an anonymous party on social media, and hundreds of protesters gathered in Algiers ahead of what could be the biggest demonstrations yet in the capital and other cities.

Riot police have been deployed in growing numbers in recent days, but the military has so far stayed in its barracks.

“Today will be a decisive day,” said Mohamed, a teacher in Algiers.