A military plane carrying over 200 personnel crashed near Boufarik airport near Algerian capital Algiers.
A total of 257 people were killed, majority military, the defence ministry said.
Emergency services converged on the area near the Boufarik military air base after the crash.
The plane was on its way to Tindouf in the south of the country, according to the Reuters news agency, where refugee camps from long-running territorial disputes in Western Sahara are located.More news: Polls close in key Hungarian parliamentary election
Passengers aboard the plane included 26 members of the Western Saharan Polisario independence movement, an official in Algeria's ruling FLN party said.
"There are more than 100 deaths".
Update: 4:45 a.m. EDT - According to local reports, all the over 100 troops onboard the military plane which crashes near an airport in Boufarik, Algeria, are dead. The army chief's office later confirmed on its Facebook page that the crash was due to a "technical failure" and that the pilot died of his injuries on the way to a military hospital in nearby Taungoo town.
Emergency services later confirmed that the death toll now sits at 257.More news: Kimi Raikkonen's auto hits Ferrari mechanic after tire change
Since it was first reported, the death toll in the crash has continued to climb. Footage captured by witnesses showed a huge plume of black smoke billowing from near the runway.
The Algerie Presse service agency said the Iliouchine-type plane was headed for Bechar in south-western Algeria.
The Defence Ministry said the head of the Army ordered an investigation into the crash. It is widely used for both commercial freight and military transport.
There was one survivor from the accident, in which the C-130 crashed into a mountain amid bad weather conditions.More news: IPL 2018, Kolkata Knight Riders vs Royal Challengers Bangalore, Match Preview