Denver police were searching for a high school student Wednesday who shot and wounded two school employees who were checking the suspect for weapons as part of a safety protocol, authorities said.

The attack happened at Eastern High School in the City Park area just before 10am local time (4pm GMT).

Authorities know the identity of the suspect and are looking for him, Denver Police Chief Ron Thomas said during a news conference. Police and school officials have not released who the suspect is.

According to the police chief, the student was specially searched at the beginning of each school day.

While the officers, both men, were conducting a search, several shots were fired, Ron Thomas said. The gun that was fired has not been found.

The victims were taken to the hospital, with one man in critical condition and undergoing surgery and the other in critical but stable condition, Thomas said.

In 2022, there were dozens of shootings at American schools that resulted in death or injury.

One of the worst attacks occurred in May, when a gunman killed 19 children and two adults in Uvalde, Texas.