Severe winter weather is gripping parts of Japan that were struck by the devastating earthquake on New Year's Day. Authorities warn rain and snow may raise the risk of mudslides as the ground has been loosened by the quake and more recent tremors.

Daytime highs will not rise much in those places on Saturday, with the mercury expected to reach only 2 degrees Celsius in Wajima City and 5 degrees in Kanazawa City. Both municipalities are in the hard-hit prefecture of Ishikawa, central Japan.

Increasing numbers of people in the quake-affected areas are falling ill as they endure prolonged stays in shelters. The number of deaths believed to be due to disaster-related causes is also growing.

Meanwhile, seismic movement continues in Ishikawa's Noto region and surrounding areas, with strong jolts recorded occasionally since the January 1 quake.

Quakes with an intensity of 1 or greater on Japan's scale of zero to 7 were recorded more than 1,300 times as of 8 a.m. on Saturday. They included a quake that shook Ishikawa's Shika Town with an intensity of 4 shortly after 4 a.m. on Saturday.

The Japan Meteorological Agency is urging people to stay vigilant against tremors with an intensity of around 5 or higher for about the next 30 days.

Stormy conditions, including heavy snow, could also batter the quake-stricken areas as well as northern and eastern Japan, from Sunday through Tuesday.

People are urged to exercise extra caution toward quake-damaged buildings, as they may collapse under the weight of snow.