Two classmates took the stand Monday as testimony continued in the trial of Abel Cedeno, the Bronx teenager accused of a fatal 2017 high school stabbing.

The classmates testified about what led to the deadly altercation between Cedeno and 15-year-old Matthew Mcree at the Urban Assembly School for Wildlife Conservation.

They told the court that a fight began when someone had thrown a paper ball where Cedeno was standing. The student witnesses testified that words were exchanged between Mcree and Cedeno, and that the two starting fighting.

A nine-second cellphone video of the stabbing was also shown as part of the prosecution's case. A police interview with Cedeno was also shown. In the police video, Cedeno told investigators that Mcree struck him, and that he purchased the knife for protection. He also said that he had been harrassed because of his sexuality.

Ariane Laboy, who survived the stabbing, is scheduled to take the stand on Tuesday. Prosecutors say Laboy was stabbed six times.

If convicted, Cedeno faces a maximum of 50 years behind bars.