People walk in snow in front of Tokyo Station in Tokyo, Japan, Jan. 22, 2018. (Xinhua/Ma Caoran)

TOKYO, Jan. 22 (Xinhua) -- The Greater Tokyo region was hit by heavy snow Monday causing disruption to traffic, with the weather agency warning the snowfall was expected to continue through Tuesday.

The Japan Meteorological Agency (JMA) said a low pressure system and a rain front moving over waters south of Japan's main island from east to west has left heavy snowfall on mountainous regions in the west, before moving on to the Kanto-Koshin region, including central Tokyo.

With the low pressure system moving eastward, areas in Tohoku and Hokkaido have also been blanketed in snow, the JMA said, with snowfall expected to reach 30 cm in Kanto-Koshin and Tohoku regions by 6 a.m. local time Tuesday.

The Hokuriku to Chugoku regions in central and western Japan can expect 20 cm of snow, while northern Kyushu and Shikoku could see snowfall reaching 15 cm, the JMA said.

In Tokyo specifically, 10 cm of snow is expected throughout all of the city's 23 wards, and 30 cm in other areas through Tuesday.

As of Monday evening, Japan's public broadcaster NHK said that major arterial routes linking Tokyo, including the Tomei and Shin-Tomei Expressways, as well as the Metropolitan Inter-City and Shuto Expressways, were partially closed due to adverse driving conditions.

Local media also reported that flag carrier Japan Airlines canceled more than 20 flights Monday afternoon, with around 5,000 people being affected.

The JMA said that if two further low pressure system develop as expected above the Sea of Japan and south of the island, the cold front could continue until Saturday.

Disaster Management Minister Hachiro Okonogi warned on Monday that heavy snow could fall in parts of Japan unaccustomed to such weather.

At a meeting of ministries and agencies, Okonogi called on the public to stay vigilant and informed of the latest weather updates and refrain from traveling when the snow is likely to be the heaviest.