Two men arrested earlier this week in connection with the death of a 29-year-old nurse are suspected of following her from a building housing a gym that she went to before they kidnapped her in a nearby parking lot, investigative sources said Thursday.

Security camera footage shows two men forcing their way into the car of Mayuko Uchiyama and driving off in the late afternoon on May 26 in Hamamatsu, Shizuoka Prefecture.

Her car was found in Kuwana, Mie Prefecture, about 100 kilometers northwest of Hamamatsu, and her body was found buried in Fujieda in Shizuoka on Saturday.

Mitsuru Suzuki, 42, and Motoki Ito, 28, both arrested on suspicion of illegally confining Uchiyama, have told investigators they became acquainted with each other through an internet message board, which included a post for "profitable" work, and met in person for the first time on the day of the attack. They have told police they were not acquainted with the victim.

2 men arrested in connection with woman's body abandoned on mountain

Suzuki turned himself in at a police station in Nagoya on Monday, and both have admitted to abducting Uchiyama but denied burying her body.

A separate security camera captured the two with another man, leading the police to suspect at least three were involved in the attack.

Authorities began looking for Uchiyama after her family reported her missing two days after the kidnapping.

There have been murders and other serious crimes committed by people who solicited accomplices online, but authorities have struggled to take countermeasures, particularly with the evolution of the dark web, which provides a space for untraceable online activities.

In a 2007 murder in Nagoya, 31-year-old Rie Isogai was abducted and killed by three men who were only acquainted through a website. One was given a death sentence, while the other two were given life terms.

(Parking lot where the victim was kidnapped)