Content Warning: This story contains mentions of gun violence.

Northwestern announced Tuesday morning it was not aware of any injuries in relation to reports of shots fired on Northwestern’s Chicago campus Monday evening.

University Police said they became aware of shots fired via a campus emergency callbox at 8:55 p.m. and sent an alert to the community four minutes later. Alerts continued until police determined the situation was secure and sent an all clear as of 10:33 p.m.

Three people were initially detained by NUPD, the school said, but said it is not clear whether they were involved in the incident. The University added none are believed to be affiliated with NU.

A previous message said that gunshots were reported outside Wieboldt Hall on Chicago Avenue after an initial alert informed community members of an “active threat event” on the Chicago campus. The alert — sent out about 10 minutes after shots were heard — instructed recipients to “Run, Hide, Fight,” “Take proper shelter,” “Lock and/or barricade doors,” and “Await further information.”

Second-year Pritzker student Fernando Harris said he was inside the law school when he heard a gunshot. Harris said while he quickly realized the altercation was of a personal nature and likely did not pose a threat to students, he sees how the alerts could have been frightening to students with less information.

According to Chicago Police communications, a third-party caller reported hearing one shot and witnessing an armed female and a group of people fighting. An eyewitness video shared with The Daily corroborates that description, depicting three individuals arguing on Chicago Avenue as one of them points a gun at a fourth individual.

Second-year Pritzker student Nima Ostowari said he was in a nearby lecture hall studying for upcoming final exams when he received the initial alert about the incident. He said the text sent him into “panic mode,” prompting him to barricade the door and hide.

“My experience was chaos associated with getting that text out of nowhere and suddenly being like, ‘I might die,” Ostowari said. “Then gradually we got the texts updating us, and finally we were in the all clear.”

This is a developing story and will be updated as more details become available.