UTSUNOMIYA, TOCHIGI PREF. ¨C Four 16-year-old boys who have been arrested for allegedly carrying out a robbery-murder in Tochigi Prefecture last week met the couple suspected of ordering them to commit the crime for the first time on the day of the incident, investigative sources said Tuesday.

The couple, Kaito Takemae, 28, and his wife, Miyu, 25, from Yokohama, are believed to have lent a white luxury sedan to the four teens, who used it to travel to the crime scene.

The boys, all from Kanagawa Prefecture, are believed to have received instructions from the couple via their smartphones.

The Tochigi Prefectural Police suspect that one of the four boys was recruited by a higher-ranking member of a loosely organized ³Ù´Ç°ì³Ü°ù²â¨± crime group and was later introduced to the couple.

In collusion with the couple, the four boys are suspected of having broken into a house in the town of Kaminokawa, Tochigi Prefecture, on Thursday morning and stabbed Eiko Tomiyama, 69, to death.

At least 20 stab wounds were found on Tomiyama¡¯s body, and her two sons, who rushed to the scene, were also attacked.

After carrying out the attack, two of the four boys fled the crime scene in the luxury car. Another was spotted by investigators while walking near the site on the day of the crime, while the other hitchhiked back, according to investigative sources.

The prefectural police believe that the couple lent the car to the boys on the day of the robbery-murder incident.

There are indications that the boys made contact with the couple after they traveled to Tochigi in the car, and at least one of the boys told police that the couple had ordered them to carry out the attack.

The four boys were successively arrested between Thursday and Saturday. Kaito Takemae was taken into custody on Sunday at the departure gate of the international terminal at Tokyo¡¯s Haneda Airport, while his wife was found at a hotel in Kanagawa with their 7-month-old daughter.