University officials are encouraging students to take safety precautions, as the Champaign Police Department and University police continue to search for the suspects responsible for four armed robberies that took place on Nov. 18 and 19 on campus.

"We have no additional information," said Detective Robert Rey of the Champaign Police Department. "The descriptions of the suspects are pretty common and there may be two or more suspects."

Rey said that he has noticed an increase in robberies when it gets closer to the holiday season, especially on college campuses.

Of the four armed robberies that occurred, one was on Nov. 18 at the 400 block of West Columbia Avenue where a pizza delivery driver was held at gunpoint and robbed of his money and cell phone. The other three were a series of robberies beginning at 1 a.m. on Nov. 19. Different victims were robbed at the 700 block of South First Street, 100 block of East John Street and the 500 block of South Fourth Street.

Gary Spear, a criminal analyst with the Champaign Police, said there have been more armed robberies in the Champaign area since Nov. 19, but they have not necessarily been on campus and not as serious as the previous four.

University police officers have also been collaborating with Champaign and Urbana police officers to find the suspects of the armed robberies.

"We share information on a daily basis," said Capt. Kris Fitzpatrick.

Fitzpatrick said she would not discuss any details of the cases, or describe any investigative strategies.

There are no additional measures the University is taking for safety, but there are already safety options the University encourages, said Dean of Students Bill Riley. One of those options is emergency cell phones.

Larry Liddle, member of the Communications and Customer Service division of the University, headed the distribution of emergency cell phones last year after a series of attacks on women.

Liddle is responsible for collecting deactivated cell phones from University faculty, testing the phones and sending them to the Office of the Dean of Students for distribution upon request.

The phones are offered free of charge and are programmed so the user can only dial 911, said Dave Shore, chair of the Illinois Student Government's Campus Safety committee. Students can check out a phone for up to one school year, he said.

When the program began, the requests were very high for the cell phones, but they have gone down over the year.

Last year the program was an initiative from the Office of the Chancellor, but the Dean of Students called Liddle about a month ago to send out requests for more cell phones.

Liddle's division sends about 10 to 15 cell phones at a time, once they have been tested.

Riley said the cell phones are charged and ready for students at the International Student Affairs Office and the Office of the Dean of Students.

ISG Campus Safety committee members are talking with officials about the undergraduate, main and Grainger libraries offering cell phones by the middle of the spring semester, Shore said. Committee members hope to offer the phones at IMPE and the Illini Union as well, he said.

"(Blue emergency) phones are good, but they're not constantly by your side," Shore said.

Riley said that within the year the program has been running, users have been 70 to 75 percent international students, because many in state and out of state students seem to have cell phones.

"We do not know how effective these cell phones are," Riley said.

Riley also urged students to make use of other safety options such as the buses with extended hours and Saferides.

— Jeremy Pelzer contributed to this report.