China executed Yan Yanming, a 21-year-old man

China executed Yan Yanming, a 21-year-old man, for stabbing nine students to death as they slept, state media said. 
Yan broke into the high school dormitory in the central province of Henan in November and stabbed 12 students, the most serious of a recent wave of school attacks.
Six died on the spot and three died later in hospital, the Beijing News said.
The newspaper did not explain what drove Yan to kill the students, only that he hated them and there had been some dispute.  Yan was arrested when his mother turned him in to police after he attempted suicide at home, state media reported.