Two staff members were injured, one of them critically, in a shooting at East High School Wednesday morning, according to the Denver Police Department (DPD).

According to 9News, a student at the school, who had a safety plan in place to be searched for weapons before entering the school, is the suspect in the shooting.

It was during a search Wednesday morning that the student shot the staff members, who are both administrators, DPD Chief Ron Thomas said. The shooting was in an office area, away from other students.

The student, a juvenile, fled the school, but Thomas said they know who he is and were working to find him. He said they had not yet located him or recovered the weapon used.

The victims, both men, were transported to area hospitals, according to DPD. DPD said one of them was in serious condition, the other was undergoing surgery for treatment of life-threatening injuries.

A student was taken to the hospital related to some type of reaction but was not hurt in the shooting, according to DPD.

Denver Police first tweeted about the shooting at 10:05 a.m. on Wednesday morning.

The Denver Public School District said in a tweet that the school was placed on lockdown due to police activity. The district went on to say that students were being held in their period classrooms until further notice.  In a follow-up tweet, DPS said they were working on a release plan for students.

They plan to do a controlled release once DPD allows it. Parents will be able to pick up their students at 17th and Esplanade, the district said. Students who drove will be escorted to their cars and will be allowed to leave.

Students who ride the bus will be held until their bus arrives. DPS also said they were working with RTD to increase the number of buses on the 15 line to help students get home.