A court in central China has sentenced a kindergarten teacher to death for poisoning two dozen pupils and killing one after a dispute with a colleague.

The teacher, Wang Yun, added nitrite to porridge that was fed to the other instructor’s class for breakfast on March 27, 2019, according to a ruling issued on Monday by the Jiaozuo Intermediate People’s Court in Henan Province.

The teachers had a dispute over “student management questions,” the court said, and Wang had sought to poison her rival’s class.

Several students who ate the porridge began vomiting and were sent to a hospital. Of the 25 who were poisoned, one died and 23 others fell ill, the court said.

“Wang Yun’s criminal motives are despicable, her viciousness is extremely deep, her criminal methods and plot are extremely bad, and the consequences are particularly serious, and she should be punished severely in accordance with the law,” the court said in its ruling.

In 2017, Wang poisoned her husband by putting nitrite she had purchased online in his water glass after an argument, the court said. He was sickened but survived. Nitrite is a type of salt often used in curing meats but can be toxic when ingested.

School shootings are almost nonexistent in China because of strict firearms restrictions, but students are still sometimes targeted in acts of mass violence.

Two students were killed outside a primary school in Shanghai in 2018 by a man with a knife. Another knife attacker killed two elementary school students and injured two more in Hunan Province last year. Poison is also sometimes used as a murder weapon in school attacks.

New York Times News Service