BEIJING (AFP) - A teenager has been arrested after killing nine people and wounding four others in a knife attack in northeast China, state media reported Thursday. The 17-year-old, who was identified only by his surname Li, barged into the home of his girlfriend armed with a knife following an argument and killed two relatives of the girl, the Legal Daily said. As he left his girlfriend’s home in Liaoning province’s Xinbin county, he stabbed six more people to death and wounded five, it said. One of the injured died Thursday in hospital, the paper said. Li was arrested near the scene of the attack, late on Wednesday night, and was taken into custody, the official Xinhua news agency reported.