DURHAM, N.C. — Durham police are trying to determine if a man arrested Thursday in an attack on a Durham woman is connected to a string of violent attacks on the campus of Duke University.

Police said Sankie Allen Lennon, 53, broke into a woman's apartment Wednesday night. They said Lennon forced the 22-year-old woman to drive him to several ATMs where he withdrew money from her account.

Police said that Lennon tried to rape her, but the woman was able to ward off his attempt.

Lennon was arrested after a scuffle with police and was charged with attempted rape and burglary.

Meanwhile, the search continues for suspects in three recent attacks at Duke.

The reward for information leading to the arrest of a man who reportedly sexually assaulted a Duke freshman last week in an East Campus dorm bathroom has been raised to $5,000.

As a result of the incident and two subsequent crimes which Duke police believe are unrelated, campus police have expanded safety patrols across campus and students, faculty and employees have discussed ways they can help enhance university security.

University officials responded immediately to student requests for self-defense training classes.

Class instructors said students will learn how to get away from an attacker.

"The students approached us, they said they would like to have self-defense classes, and we thought that was a reasonable request. We had our first one last Friday, and there are two more that are scheduled," said Keith Lawrence of Duke University.

Anyone with information about the assault or the two other crimes -- a robbery attempt in Duke Gardens Feb. 2 and an attempted assault in Perkins Library on Feb. 4 -- should call Duke Oolice at (919) 684-4713.