A body found in a closet in a house in central Japan on Monday was confirmed to be that of a missing 16-year-old high school girl from Tokyo, police said Tuesday.

Masaki Eguchi, the 21-year-old resident of the house in Ichinomiya, Aichi Prefecture, was arrested for allegedly abandoning the body of Waka Kato, the police said.

Investigative sources quoted Eguchi as saying he stabbed Kato "several times" as he had "trouble" with her.

The closet was in the suspect's room, and the body was found lying face up, wrapped in cloth and secured with tape, the police said, adding that there were more than 10 stab wounds in the back of her neck and shoulders.

The police searched Eguchi's home on Tuesday.

When Kato left her home in Tokyo on Friday, she told her family she was planning to visit a friend in Aichi Prefecture whom she had met through an online game, according to the sources. She was reported missing on Saturday as her family could not contact her.

The number of criminal cases involving children under 18 who met people through social media or online games has increased in recent years, Japan's National Police Agency said.

Police authorities have been urging young people to avoid unnecessary encounters with individuals they connect with through games, as online platforms make it easy to communicate with strangers via chat features.

The agency has also been encouraging parents to supervise internet use by their children and calling for the creation of household rules, such as not sharing contact information with people they only know from online.