At least two people have died and dozens others injured in an expressway pileup in North Jeolla Province on Monday, amid slippery road conditions caused by heavy snow.

According to local police and fire authorities, some 20 vehicles piled up in a collision that occurred at 12:23 p.m. inside a tunnel on a highway connecting Suncheon and Wanju in the southwestern region.

A tank truck carrying sodium hydroxide caught on fire during the accident, causing toxic gases to fill the tunnel. Police blocked access to the road in order to help rescue efforts but faced difficulties as they assessed the scale of damage due to the black fumes. 

The accident claimed at least two lives while injuring 37 people, with some reportedly in serious condition.

Fire officials also mobilized 43 vehicles and over a hundred personnel to extinguish the flames and carry out rescue operations.

Around the same time, five vehicles were involved in a second pileup that took place several hundred meters away in another tunnel.