A 77-year-old Tokyo woman has since been identified as one of the two people killed.
A second person has been identified as the driver of a burned-out truck. Up to 26 people were injured.
Afterwards, a long line of vehicles remained on the highway - a section of which had to be closed off, as emergency crews worked at the site.
Many of the vehicles involved were described as “charred beyond recognition”.
One man caught in the incident told local media outlet NHK that he heard a loud explosion from the far side of the pile-up.
He also described seeing a fire, which he said spread to other vehicles involved.
The man said he and about 50 other people caught up in the crash spent a night in the hallway of a nearby toll gate.
Weather authorities had earlier issued a heavy snow warning at the time of the crash.
The cause of the initial crash is being investigated. However, local authorities said they believed icy surfaces likely caused the two trucks to skid.
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