A rash of armed robberies near the University of Minnesota campus in recent weeks has shaken students easing into the spring semester and renewed concerns about security on and around the campus.

The most recent attack occurred in the early morning hours Sunday, when three men wearing hoodies robbed a man who was walking in the area of SE. 8th Street and 12th Avenue SE., near campus. Police revealed few details about the three male suspects, but said the latest robbery was unlike a string of earlier armed stickups in the area.

Those crimes, police said, appear to have been the work of a pair of men in their 20s, who usually approached their unsuspecting victims after dark, flashed a black gun and stole their valuables. In three of the four robberies, the suspects made off with students' cash, electronics and school IDs. A fourth attempt was thwarted when a student yelled for help and the robbers fled.

As of Monday afternoon, police hadn't made any arrests.

Police officials contend that crime is always a concern on urban campuses like the U's, particularly ones that have experienced as much change as the U.

The area surrounding campus has undergone dramatic changes in recent years, with the construction of dozens of sleek new apartment buildings and the opening of the light-rail Green Line.

"Anytime that you have a larger number of people, and more transportation in and out, you run the risk of having more issues and challenges," John Elder, Minneapolis police spokesman, said Monday. "We're absolutely seeing an influx of people coming in from surrounding communities."

In response to the latest surge of robberies, Minneapolis police sent extra patrols near campus and the nearby Marcy Holmes neighborhood.

University of Minnesota police declined to comment on the latest string of incidents, but a university spokesman pointed to a campus security plan unveiled in 2013.

The U has spent millions in security upgrades over the past decade, including adding security cameras and door card readers to most buildings on campus and improving lighting along frequently traveled pathways. In addition to expanding its Gopher Chauffeur shuttle service, there is also a service students can call to be escorted home after dark.

In an attempt to alert students about crime, the U urges people to sign up for its new Neighborhood Safety Notice, a service that sends out information from the Minneapolis Police Department about crimes in neighborhoods surrounding the campus.

Still, some students remained wary of official assurances that campus remains safer than ever.

Junior Natalie Pederson said that she often ignores the crime alerts broadcast by the school in the wake of such attacks, but that she does practice common street smarts like not wearing earbuds at night and traveling with a group when she's out late.

"I think as a girl I'm more aware of my mortality," she said, adding that she feels men are more likely to be robbed than women. "Guys think they're invincible and put themselves in vulnerable situations a lot of the time."

Allyson Rehm, a senior at the U who has lived in Dinkytown for two years, said she plans on moving to St. Paul because of the crime and the loud weekend parties. Last year, Rehm said, a nearby party got out of hand and one of her neighbors was shot dead.

The U campus and some nearby neighborhoods saw a modest rise in violent crime last year, even though other crimes such as burglary, auto theft and arson fell overall. The Second Precinct, which encompasses campus and most nearby neighborhoods, saw robberies rise 18 percent from 2014 to 2015.

Libor Jany • 612-673-4064 Twitter:@StribJany

Youssef Rddad is a University of Minnesota student on assignment for the Star Tribune.