Police launched a massive search Thursday for a 9-year-old girl who went missing a month ago on her way home from school in southern Osaka Prefecture.

About 3,000 people, including officers from 64 police stations in Osaka Prefecture, volunteer firefighters and local residents combed through mountain forests, river banks and deserted houses for clues to the whereabouts of Yuri Yoshikawa, a fourth-grader at Kita Elementary School in Kumatori.

The search was conducted in part of the mountain forests in Wakayama Prefecture that border Osaka.

Investigators at Izumisano Police Station, which has primarily handled the case, suspect that Yoshikawa may have been kidnapped sometime around 3 p.m. May 20 on a street several hundred meters from her Kumatori home.

Initially, police said Yoshikawa was last seen at a location some 200 meters from her house at around 3:20 p.m. that day. But police now believe the girl seen by the witness was not Yoshikawa.

A classmate of Yoshikawa has told police he passed by her just before 3 p.m. on a street 400 meters from her house.

However, people who are known to have been either working or walking along the road that leads to her house at about that time told police they did not see the girl. This has led investigators to suspect she might have been kidnapped during that brief period, according to police sources.

The girl's parents -- Nagaaki Yoshikawa, 42, and Miwako, 42 -- are both teachers. They told Kyodo News earlier that they have taken leave from work to respond quickly to a possible phone call home from their daughter.

The Izumisano police have distributed 70,000 fliers asking for public cooperation, and are accepting information at (0724) 64-1234. They have so far received about 360 calls, the police sources said.