SHIJIAZHUANG - A father who was upset with a court ruling after his daughter was murdered drove a car into a group of students during their lunch break in North China, leaving 13 hospitalized, officials said Tuesday.

The injured students were not involved in the daughter's murder.

Divorced and without a stable job, Yin Tiejun, 48, ran down 23 students of Fengning No. 1 Middle School, located in the county seat of the Manchu autonomous county of Fengning, Hebei province, at noon on Monday.

Of the 13 students in hospital, one has a fractured skull, the bones in another's feet are broken and one is suffering from damaged blood vessels in his eyes. The ten others incurred only minor injuries, Fengning officials said, citing sources with the hospital.

Police said Yin lit a bottle of diesel, trying to burn down the car after hitting the students.

Police officers, who put out the fire, found a gas tank and firecrackers in the trunk of the car. However, Yin said during interrogation that these were not for an attack.

Police cleared Yin of driving under the influence of alcohol or drugs. They said he was upset with a court ruling that did not sentence all his daughter's murderers to death.

Yin was detained on charges of endangering public safety on Tuesday.

Recently, there have been a number of cases involving school children being attacked, both home and abroad.

On December 14, a man broke into an elementary school in central Henan Province, wounding 23 students with a knife. None of the injured were critically hurt, but the attack spread fresh fears among parents on their children's safety.

Initial police investigations indicate that "doomsday" rumors had driven the 36-year-old to carry out the attack.

Also this month, the United States was shocked by one of the deadliest school attacks in its history. A gunman stormed Sandy Hook Elementary School in Newtown on December 14, killing 20 children and 6 adults, after murdering his mother at her home. He committed suicide after the shooting rampage.

Related stories:

22 students chopped to injuries in Central China

Police catch man suspected of injuring 22 students

11 children killed in school bus accident

Police release details on children's attacker

Children's injuries 'devastating'