Four armed robberies have occurred on or near the University of California at Berkeley campus in the past week, and police are beefing up patrols and reminding students to remain vigilant.

The latest robbery was reported around 7:40 a.m. Tuesday. A male student told police he had been walking north on the path between North Gate and University Drive at about 7:15 a.m. when two men approached him.



The suspects demanded his property and one showed the victim the handle of a gun in his pocket, according to police. The victim gave up his belongs and the suspects ran away toward Hearst Avenue.



The victim was not injured.



Police searched the area for the suspects, but they were not found.



The first was described as a black man between the ages of 18 and 20, standing about 5 feet 10 inches tall with a medium build. He had some facial hair on his chin and was wearing a black hooded sweatshirt and black pants.



The second suspect was also black, and between 20 and 23 years old standing about 6 feet tall. He had a slender build and was armed with a black handgun.The armed robbery follows three others since last Thursday.



A 57-year-old female university employee was mugged by a suspect with a gun around 5:30 a.m. Thursday near Berkeley Way and Oxford Street. Later that day, a 19-year-old female student was held up at a bus stop at 2424 Channing Way, near Telegraph Avenue.



On Sunday night, a student's phone was taken at gunpoint by two men near the Moffitt Library on campus.



UC Berkeley police Lt. Marc DeCoulode said series of crimes is "unusual."



He said police have adjusted staffing to have more officers patrolling campus, particularly in the early morning and evening hours.



DeCoulode noted that although none of the robberies have resulted in serious injury, there is always that possibility when weapons are involved.



He advised students, faculty and staff to be aware of their surroundings when walking in the campus area. One of the victims was targeted for a phone, he said, which serves as a reminder to put away electronics while walking.



He said many of these robberies are likely opportunistic.



"It's just one of those cases where we have some people out and they have the opportunity," he said.



Fliers have been posted on campus about the increase in robberies, and alerts have gone out through an online system to warn the community about the crimes, Decoulode said.



UC Berkeley police Lt. Eric Tejada called the robberies "troubling." They are being investigated to see if there are any connections but no links have been found so far, police said.