The number of people taking refuge at shelters in earthquake-hit western Japan's Osaka Prefecture grew by 1,000 on Wednesday as rain that started in the early hours sparked fears about landslides, leading some residents to return to the facilities.

As of 8 a.m., 1,700 people were staying in public shelters in the prefecture, marking a sharp increase from 580 as of Tuesday night, according to the Osaka prefectural government.

The weather agency issued a heavy rain warning for the city of Ibaraki and other parts of the prefecture, forecasting up to 150 millimeters of rainfall in the 24 hours until 6 p.m. Wednesday. Some areas may see torrential rain with thunder, it said.

Local authorities have covered house roofs damaged in Monday's earthquake with plastic sheets to prepare for the rain and advised some 1,800 people to evacuate fearing possible landslides.

Most public elementary and middle schools reopened in hard-hit Takatsuki city but the city of Minoo decided to continue suspending classes at their schools as a precaution against landslides.

"I am scared of the aftershocks so I am staying at the evacuation center," said Moriyuki Nakahashi, 67, in an elementary school's gymnasium in Takatsuki. Nakahashi sustained a cut on his forehead that had to be stitched after a bookcase fell on him while he was asleep.

"My house roof is already letting water in, and I am worried because I have not spread a sheet over it," he added.

"I want to stay here (evacuation center) while there are still earthquakes, but I don't know how long I will be allowed to do so," said 85-year-old Chizuyo Kobayashi also in Takatsuki.

Kobayashi, who has physical disabilities, said she was carried out of her apartment on the sixth floor to the ground floor using the stairs as the elevator there failed after the quake.

The magnitude 6.1 quake that rocked the area on Monday morning, with five fatalities reported, was the biggest in the Kansai area since a magnitude 7.3 quake devastated Kobe in adjoining Hyogo Prefecture and its vicinity in 1995, killing more than 6,000 people.

The victims of Monday's quake included Rina Miyake, a 9-year-old girl in Takatsuki who was hit by a concrete wall that collapsed on her as she was walking to school.

Police have launched an investigation into the fatality, suspecting it could be a case of negligence resulting in death due to shoddy construction, according to investigative sources.

The school remains closed while other public schools in the city resumed operation.

Meanwhile, Sharp Corp. said it is considering ways to offer replacements for Sharp-made televisions and other products damaged in the quake for half their regular price as an expression of "condolences from a company that was born and bred in Osaka," executive Yoshihiro Hashimoto said.

The major electronics firm is headquartered in Sakai, Osaka Prefecture.