President Xi Jinping sent a condolence message on Thursday to Algerian President Abdelaziz Bouteflika over the military transport plane crash that killed 257 people in the worst aviation disaster in the North African nation's history and plunged the country into mourning.

In the message, Xi, on behalf of the Chinese government and people, mourned the victims and expressed great sympathy and sincere condolences to those injured and the families of the victims.

Premier Li Keqiang also sent a condolence message to Algerian Prime Minister Ahmed Ouyahia.

The plane went down in a field just outside a military base in Boufarik, 30 kilometers south of Algiers, and was devoured by flames, killing 247 passengers and 10 crew members, the Defense Ministry said.

There was no official mention of survivors.

Several witnesses told Algerian TV network Ennahar that they saw flames coming out of one of the plane's four engines just before it took off.

"The plane started to rise before falling," an unidentified man lying on what appeared to be a hospital bed told Ennahar TV. "The plane crashed on its wing first and caught fire."

The four-engine Il-76 made its maiden flight in 1997, according to Aviation Safety Network. The plane has been in production since the 1970s, and is widely used for both commercial freight and military transport.

President Bouteflika ordered three days of mourning starting immediately and prayers for the dead on Friday at mosques across the country.

Algeria is vast and plane flights are often the best way to traverse Africa's largest nation.

It was the first crash of an Algerian military plane since February 2014, when a US-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. Only one person survived.

AP contributed to this story.

zhangyunbi@chinadaily.com.cn