The Algerian president, Abdelaziz Bouteflika, has declared three days of national mourning after a military aircraft crashed, killing almost everyone on board.
An Algerian military statement, released on Tuesday, said there were 78 people on board the C-130 that was flying in poor weather conditions when it crashed into Djebel Fertas mountain shortly before it was to land in Constantine.
It said that of the 78 people, 77 were dead. Only one person survived, having sustained serious injuries, and was being operated on in Constantine military hospital.
But there were conflicting reports of the death toll, with some putting the figure as high as 103. A senior military official told the official APS news agency that 99 passengers, and four crew members had been on board the plane.
Most of the passengers were off-duty military personnel and their families. At least 57 fatalities, among them women and children, were pulled from the wreckage.
The transport plane took off from Algeria's southern Tamanrasset province and was bound for the eastern city of Constantine, 350km east of Algiers, Reuters said.
Broken in three parts
Witnesses in the area told Associated Press that the plane clipped a mountain and then crashed and local reporters said the plane could be seen broken into three parts.
Military and civilian personnel were deployed for a search and rescue operation in the snowy crash site, the independent El Watan newspaper reported.
Tamanrasset, in the far south of Algeria, near the border with Mali, is the main base for the country's southern military operations. Extra troops and equipment have been stationed there in recent months as part of efforts to beef up surveillance of Algeria's frontiers with Mali and Libya, following a deadly hostage-taking by armed groups at a desert gas plant in January last year.
Tuesday's plane crash would be the worst in Algeria since 2003 when an Air Algerie jet crashed shortly after takeoff from Tamanrasset, killing 102 people.
In December 2012, two military jets conducting routine training operations collided in mid air near Tlemcen, in Algeria's northwest, killing the pilots of both planes.
A month earlier, a twin-turboprop CASA C-295 military transport aircraft, which was carrying a cargo of paper for the printing of banknotes in Algeria, crashed in southern France.
That plane was carrying five soldiers and a representative of the Algerian central bank, none of whom survived.