TOKYO (AP) — Weather officials in Japan predicted more heavy snow Thursday, a day after nearly 800 vehicles were trapped for hours on an expressway in central Japan.

The 6-kilometer (4-mile) traffic jam happened after two trailers got stuck in the snow Wednesday, forcing soldiers to come in and help free the vehicles.

Japan’s Meteorological Agency said as much as 60 centimeters (24 inches) of snow could fall in the Tohoku region through Friday, according to Japan’s Kyodo news agency, with heavy snow also expected on the northern island of Hokkaido and in other areas.

The traffic jam occurred on the Meishin Expressway in Gifu prefecture. Two children in a stranded vehicle became sick and were taken to a hospital, Kyodo reported.

The Central Nippon Expressway Co. closed the road and mobilized snowplows and tow trucks to clear the stranded vehicles, while delivering snacks, drinking water and portable toilets for those trapped. The Ground Self-Defense Force, Japan’s army, dispatched troops to join relief efforts at the request of the governor of Gifu.

Cold air from the west formed a cold front that caused heavy snow to fall in Japan’s north-central region. The severe weather also led to accidents in a number of locations.