A nine-year-old and a 12-year-old were arrested Tuesday by the NYPD after they put rat poison in their teacher's water bottle on Monday.

The unidentified fourth grade students poisoned 62-year-old Johanna Cherepany in her P.S. 315 classroom in Flatbush, Brooklyn. Cherepany's blood pressure rose and she was nauseated, but she suffered no serious injury.

The water was tainted at the performing arts school around 12:30 p.m. on Monday. After school, a student who witnessed the incident told her mother what the boys had done, and the mother called Principal Judith Ranft and to report the poisoning.

After being treated by a physician, Ms. Cherepany filed a report with the NYPD's 70^th Precinct.

The two children were charged with attempted second degree assault, reckless endangerment, and criminal possession of a weapon. The New York Post reports that more rat poison was found in the nine-year-old's backpack.

The motive for the poisoning is unclear. Former P.S. 315 substitute teacher Mussolini Mombrun said that Cherepany is a good teacher.

"She cares about her kids. She gets the job done," Mombrun told the Post. "I feel bad for her. She is a wonderful person."

The former sub added that the children of the school are extremely unruly.

"It's chaos in there," he said. "The kids are out of control. They don't listen. They curse. I have complained but the principal does not follow-up with complaints. The kids [involved] don't get transferred and more chaos happens."

Mombrun stated that he was fired from his teaching position.

New York City Department of Education spokesperson Marge Feinberg said that the school system is committed to the welfare of its staff and students.

"We are greatly relieved that the teacher is recovering and we continue to closely monitor this situation," she said in a statement. "Ensuring the safety of our entire schools community is our priority, and while this matter is still under investigation, we will take swift and appropriate action."