A school bag belonging to missing Japanese student Megumi Suzuki was found Wednesday by police in a suburban district of Adelaide, South Australia, heightening fears over her whereabouts.

Suzuki, 18, from Shizuoka Prefecture, was last seen Aug. 3 in Adelaide's central shopping district.

Police officer Neil Tank said the black bag was found in some bushes, while Suzuki's school identification card, books and a pencil case were found strewn over an area of some 500 meters.

Investigators found the items following a tip from a member of the public.

"It appears the bag and its contents may have been thrown or dropped from the bridge onto Hill Street (in the northeastern Adelaide suburb of Campbelltown)," Tank said. "It appears that the items had been lying where they were found for several days."

Suzuki's mobile phone was not among the items recovered. "Every day she is missing our concerns are heightened. It has now been 12 days since she was last seen," said Tank.

Police in South Australia launched a public appeal Tuesday for information regarding Suzuki's disappearance. Police said in a statement Wednesday that they will conduct a door-to-door investigation and will examine security tapes from train stations and nightclubs Suzuki was known to frequent.

At the time of her disappearance, Suzuki was studying at a private secondary college and living at an international students' residence on Adelaide's outskirts.

She studied in Adelaide between October and April, before returning in July after a brief visit back to Japan.

Her mother arrived from Japan on Tuesday to assist police with their investigations.