Algeria's ailing President Abdelaziz Bouteflika has returned to the country after two weeks in a Swiss hospital, state media say.
A plane carrying the 82-year-old leader landed at Boufarik military airport near the capital, Algiers, as protests against his 20-year rule continue.
Teachers and students have gone on strike at several universities, with thousands joining demonstrations.
They are against the president's plan to seek a fifth term in office.
Mr Bouteflika has said that the mass demonstrations, which broke out last month and represent the biggest threat so far to his rule, could plunge the country into "chaos".
On Sunday, thousands of students took to the streets of Algiers, waving the Algerian flag and chanting: "Bouteflika, there will be no fifth term."
Many shops in the city have been closed, and Reuters reports that train services have been suspended.
On Friday, tens of thousands of people joined protests thought to be the biggest in the capital in 28 years.
Riot police fired tear gas to prevent the mostly peaceful groups from reaching a road leading to the presidential palace, and local reports said 195 people were detained by the security forces.
Many who demonstrated that day initially gathered at university sites before heading onto the streets.
Algeria reportedly has more than 1.7 million students. More than a third of these live on campus, but many others travel long distances to study from family homes.
Meanwhile, the Algerian presidency confirmed Mr Bouteflika, who has rarely been seen in public since having a stroke in 2013, had returned after two weeks of "periodic medical checks" in Switzerland, state media APS reported.
Privately-owned Ennahar TV reported that the plane had landed at Boufarik military airport but did not broadcast any footage of the flight.
Instead, it carried a live flight tracker map which showed the plane approaching Blida Province, where the airport is based.
The plane that was photographed in Geneva's Cointrin airport earlier on Sunday is thought to be the same one that flew him over on 24 February.
Mr Bouteflika's office previously insisted that he was just going to Geneva for routine health check-ups, but it led to speculation that his condition was far more serious.
What do the protesters want?
The wave of protests was triggered by the announcement last month that Mr Bouteflika would seek a fifth term in office in April's election.
Mr Bouteflika later released a statement saying that he would step down early if re-elected - but this has not placated the demonstrators.
Many young Algerians are frustrated by a lack of economic opportunity and by what they perceive as the corruption of an elite that has governed the country since it gained independence from France.