ALGIERS, Algeria (AP) -- An Algerian military plane carrying soldiers and their families crashed soon after takeoff Wednesday into a field in northern Algeria, killing 257 people in what appeared to be the North African nation's worst-ever plane crash.
Algeria's Defense Ministry said those killed included 247 passengers and 10 crew. The cause of the crash was unclear and an investigation has been opened.
Algerian authorities did not mention whether there were any survivors but one witness reported seeing some people jump out of the aircraft before it crashed at 7:50 a.m. Wednesday.
The flight had just taken off from the Boufarik military base, 30 kilometers (20 miles) southwest of the capital Algiers, for a military base in Bechar in southwest Algeria, according to Farouk Achour, the chief spokesman for the civil protection services. It was scheduled to make a layover in Tindouf in southern Algeria, home to many refugees from the neighboring Western Sahara, a disputed territory annexed by Morocco.
The Soviet-designed Il-76 military transport plane crashed in a farm field with no people nearby, Achour said.
Algerian TV Dzair said five people were in a critical state but it's unclear whether they were inside the plane when it crashed.
Footage from the scene showed thick black smoke coming off the field, ambulances and Red Crescent vehicles arriving at the crash site and body bags lined up in the field.
Several witnesses told Algerian TV network Ennahar they saw flames coming out of one of the planes' engines just before it took off. One farmer said some passengers jumped out of the aircraft before the accident.
"The plane started to rise before falling," an unidentified man lying on what seemed to be a hospital bed told Ennahar TV. "The plane crashed on its wing first and caught fire."
The victims' bodies have been transported to the Algerian army's central hospital for identification.
The prime minister's office said lawmakers and officials observed a minute of silence as a tribute to the victims.
The Il-76 model has been in production since 1970s and has an overall good safety record. It is widely used for both commercial freight and military transport. The Algerian military operates several of the planes.
It was the first crash of an Algerian military plane since February 2014, when a U.S.-built C-130 Hercules turboprop slammed into a mountain in Algeria, killing at least 76 people and leaving just one survivor.
The previous deadliest crash on Algerian soil occurred in 2003, when 102 people were killed after a civilian airliner crashed at the end of the runway in Tamanrasset. There was a single survivor in that crash.
Also in 2003, 10 people died when an Algerian Air Force C-130 crashed after an engine caught fire shortly after it took off from the air base near Boufarik, according to the Aviation Safety Network.