A 17-year-old Japanese boy suspected of killing and beheading his mother went to an internet cafe with her head in a bag and watched a music DVD before turning himself in, media reports said.

The teenager, arrested yesterday on suspicion of murder, spent about two hours at the cafe watching a DVD of a hip-hop group in his cubicle and then took a taxi to a local police station, the reports said.

Media quoted employees of the cafe as saying the youth, a student at a local high school, was carrying a school bag and that one of his hands was wrapped in bandage.

Police in rural Aizuwakamatsu, Fukushima prefecture, 200km north of Tokyo, arrested the teenager after he walked into a police station early yesterday carrying a severed human head in a bag. Officers found a beheaded body in the apartment where he lived.

The teen - who had not been attending school recently and was being treated by a psychiatrist - told police he killed his mother on Monday evening while she was asleep, media said.

Japan has been shocked by a number of sensational and gruesome crimes by youths in recent years, including the murder and beheading of an 11-year-old boy by a 14-year-old schoolboy in the western city of Kobe in 1997.

In 2004, an 11-year-old schoolgirl stabbed a classmate to death at their school, prompting calls for harsher punishment against juvenile crime.

A bill to lower the age at which minors can be sent to reformatories from 14 to 12 was passed by the lower house of parliament last month. The bill remains controversial and still needs approval from the upper house before becoming law.

Government statistics show that overall juvenile crime including murder by minors - those under 20 - has declined in recent years.