Raleigh, N.C. — Police at North Carolina State University are being especially alert after two armed robberies in two days, and they are urging the university community to do the same.

Investigators said one victim, a graduate student, was leaving a building on the Centennial Campus when two men armed with a handgun demanded his wallet late Tuesday afternoon.

Two male students told police they were near 2110 Avent Ferry Road at about 9 p.m.Monday when a man wearing a mask and armed with a knife robbed them.

"It's very concerning, not only to us, but to the campus community," said Capt. Jon Barnwell, with NCSU police.

Police said they did not know if the Tuesday robbery was related to the Monday case, but they were looking at the possibility.

“In light of the recent robbery that we had last night, we don't want this to escalate to a pattern, so we are really aggressively chasing this down,” Barnwell said Tuesday.

The robber Monday fled in a red sport utility vehicle, possible an early 2000s model Ford Explorer.

There have also been several recent break-ins at campus-area apartment complexes. The Avent Ferry Complex had as many as five robberies last week.

Natasha Herting, who is running for student body president, said burglars broke into her College Inn apartment while she and her roommates were sleeping.

"It was really scary just to think that you have no control – that someone could be in your apartment and you have four girls alone,” she said.

N.C. State students with whom WRAL spoke said the recent rash of crimes has them on alert.

“I'm thinking whether I’m safe walking down to my lab or not,” Devesh Diwari said.

“Yeah, it’s definitely alarming. Definitely walk in groups, that's what I would say,” Zach Fitzgerald said.

Authorities said Wednesday that there was no connection between the robbery near Centennial Parkway and a Tuesday night robbery at a Handy Hugo's convenience store at 6922 Buffaloe Road.

N.C. State sent out e-mails to staff, facility and students about the recent crimes and offered crime prevention tips.

The campus police also said they are on heightened patrol in wake of the recent incidents. Police asked anyone with information that could help in the investigations to call 919-515-2498.