Algerian authorities have halted train and metro services in the capital Algiers on Friday amid heavy security ahead of expected protests against President Abdelaziz Bouteflika.
Mass demonstrations now entering their third week have posed the biggest challenge to the ailing 82-year-old president, who has ruled the country for 20 years and is standing for re-election on April 18.
Tens of thousands of Algerians, tired of the dominance of old guard, have been demanding that Bouteflika step down, but despite his ill health, he has submitted his candidacy papers.
On Thursday, Bouteflika issued his first warning to protesters, saying the unrest could destabilise the country.
Bouteflika has been in Switzerland since February 24 for what the presidency has described as "routine medical tests".
English 
العربية