Eight juveniles were suspected of assaulting, burying and killing a 21-year-old man in Yongchang county, Northwest China's Gansu Province; the eight suspects have all been detained by local police and the investigation is underway, Yongchang public security bureau said on Tuesday.

At 12:12 pm on July 30, Yongchang public security bureau received a report from an individual surnamed Mao, who was seeking the police's help as Mao's 21-year-old son had gone out and lost contact at 1 pm on July 29.

The public security bureau immediately launched an investigation and arrested eight suspects including a 14-year-old boy surnamed Guo.

The victim had been introduced to Guo's girlfriend, stoking feelings of resentment by Guo who felt the victim was stalking his girlfriend and planned to take revenge. Guo asked the other seven suspects to assault the victim beating him unconscious before burying him, according to local police.

The suspects shot videos during the process and the body was found on a hillside after the suspects confessed to the actions, according to police. The eight suspects confessed to all their crimes, and the investigation remains underway, Yongchang public security bureau said.