TOKYO, June 20 (Xinhua) -- Evacuation shelters in earthquake-hit Osaka Prefecture in western Japan saw a huge spike in the influx of people seeking refuge Wednesday as heavy rain in the region sparked concerns about landslides amid ongoing aftershocks.

According to the Osaka Prefectural government, around 1,700 people were staying in evacuation shelters as of Wednesday morning.

The number marked a sharp increase from the 580 evacuees seeking emergency refuge as of Tuesday night in the wake of the powerful magnitude-6.1 earthquake that rocked the region early on Monday morning.

Some city officials in Osaka Prefecture have only been able to provide evacuees with rice-based meals three times a day, using their own emergency supplies of stockpiled rice, according to local media accounts.

The city officials said they have yet to receive any food aid, despite the rising numbers of evacuees.

With gas supplies cut off until next Monday in many parts of the quake-hit region, people have been clearing the shelves in supermarkets and convenience stores of bread and microwavable food, with many complaining of being unable to eat regular, cooked food or being able to take a hot bath.

Japan's Meteorological Agency (JMA), meanwhile, has warned of possible landslides as a result of heavy rain hitting the area.

In the hard-hit city of Ibaraki and neighboring areas in Osaka Prefecture, the weather agency said it predicts as much as 150 millimeters of rainfall in the 24 hours through 6 p.m. on Wednesday.

The JMA added that some areas may experience torrential rain with thunder.

The magnitude-6.1 quake that rocked a wide swathe of western Japan on Monday morning caused five fatalities, one of whom was 9-year old girl, Rina Miyake, who was crushed when the outer wall of her school's swimming pool collapsed on her as she was walking to school.

Police investigations have been launched into the case. Engineers and seismologists have warned that similar walls in the region and beyond should be inspected for construction flaws that may or may not have been hidden by painted murals.