Two people were in custody Thursday in connection with a “suspicious incident” that prompted authorities to put Northfield High School on lockdown. 

Denver Police Chief Paul Pazen said investigators recovered a paintball gun at the school and police will present charges to the Denver District Attorney’s Office.

Pazen declined to say whether the people in custody were students or what crimes they may be charged with.

A student saw what appeared to be a gun and reported the information to the school’s security team.

“We want to commend a student who saw something suspicious, saw something that looked like a potential threat and advised the campus security team here at Northfield,” Pazen said. 

The school was placed on lockdown and officers arrived to the campus at 5500 Central Park Blvd. within three minutes, Pazen said. No one was injured during the incident. 

Denver Public Schools Superintendent Alex Marrero said there were nearly 2,000 students on campus when the school was put on lockdown. He said many of those students were “in great spirit” following the incident. 

School officials canceled class after authorities lifted the lockdown. Students were evacuated and taken by bus to a designated area where they were reunited with their parents. 

District officials said they would provide mental health services to students following Thursday’s incident.   

Police respond to an incident at Northfield High School on Thursday. Photo courtesy 9News.