A shots-fired report locked down the University of Wisconsin-Madison campus Wednesday night.

The incident was part of an alleged armed robbery in a residential area near campus, close to several fraternity and sorority houses. No one was reported injured, police said.

Two men, ages 17 and 18, were detained by police but not arrested as of Wednesday night.

Police said the incident wasn’t an active shooter situation, but they advised students and others in the area to stay indoors while police searched for the suspects.

The incident stemmed from an armed robbery, according to a police report. At about 6:20 p.m., two suspects robbed a 19-year-old man at gunpoint, taking his wallet, keys and backpack, the report said.

A friend of the victim chased the suspects as they fled on foot, the report said. A suspect then fired one shot that didn’t hit anyone.

Campus police advised students to stay indoors via Twitter around 6:40 p.m. About an hour later, police tweeted that taking shelter was no longer necessary.