Yamanashi Prefecture authorities continued their search on Wednesday for a 7 year-old-girl who went missing last month, as family members released a photo of her taken on the day she vanished.

Misaki Ogura, a first grader from the city of Narita, Chiba Prefecture, disappeared on Sept. 21 when she and her family were visiting a campground in the village of Doshi.

Yamanashi Prefectural Police and other authorities looked for the missing girl with a search party of around 50 people, scanning an area downstream of a brook near the campsite as well as Doshi Dam in the city of Sagamihara, Kanagawa Prefecture.

The search crew walked down the Doshi River, located near the border between Yamanashi and Kanagawa prefectures, combing the area and checking behind rocks, but no clues were found in the mountain areas or streams that were searched.

The Yamanashi police authority released Ogura's photo Monday at the request of her family and is soliciting information from the public.

"I can't regret enough not having walked with her," the girl's 36-year-old mother Tomoko told reporters Monday, thanking all those who had cooperated in searching for the girl.

The parents have been staying in a tent at the campground, and have continued searching for her day and night.

Ogura went camping with her mother, sister and her friends' family on Sept. 21. She went missing at about 3:40 p.m. after running to follow children who had gone to play in a stream.

A 55-year-old man from the town of Shimosuwa, Nagano Prefecture, who was lost for a period after joining the search, descended the mountain Wednesday morning with no injuries.

Another volunteer, a 27-year-old man who went missing on Sept. 27 after telling police over a phone that he had fallen off a cliff, was rescued two days later with his right arm broken.