Police said Tuesday there were posts on internet message boards that apparently hinted at where to look for the body of a slain 9-year-old Vietnamese girl before it was found near a drainage ditch in Chiba Prefecture Sunday.
In one message posted after 9 p.m. on Friday it said, "When it gets warm, let's take a look at a ditch to see if there is a dead girl's body," the police said.
A second message posted on another board about an hour before Linh was found said, "Go search a ditch."
Le Thi Nhat Linh's naked body was found in Abiko on Sunday. The girl disappeared Friday morning in Matsudo, a city in Chiba about 10 km away.
The Matsudo Municipal Government emailed information about the missing girl to residents on Saturday.
The police are investigating whether the posts are related to the apparent kidnap-slaying.
On Tuesday, they also discovered a school rucksack that belonged to Linh along the banks of the Tone River in the city of Bando, Ibaraki Prefecture, more than 10 km northwest of the Abiko site.
The rucksack was found on Monday and Linh's father confirmed it belonged to her on Tuesday.
The police said some clothes belonging to a girl were found about 500 meters from the riverbed. They are trying to confirm if they were Linh's.
Investigators are seeking information from nearby residents in Bando as to whether they saw anyone suspicious.
The police believe Linh was strangled at an unknown location and then dumped near the ditch in Abiko. They are scrutinizing security camera footage in a bid to find the vehicle used by the killer.