The attorney general's office announced Wednesday that it is investigating the link between 13 rapes that occurred over eight years in two college towns.

Attorney General Steve Six said there are enough similarities between the college-age victims, time of attack and manner of attack to suspect the rapes are connected. The attorney general's office would not provide any other details about what might connect the crimes, including whether authorities have any DNA or other forensic evidence.

Eight of the rapes were in Manhattan, which is home to Kansas State University, and five were in Lawrence, about 85 miles to the east and home to the University of Kansas. The 13 rapes happened from 2000 to 2008, and none was committed on campus.

Police in Lawrence and Manhattan have been investigating the crimes separately, but authorities only recently determined they had enough information to link the two cities' cases and share the findings with the public. Now, the attorney general is coordinating the investigation, which includes the Kansas Bureau of Investigation, said Six spokeswoman Ashley Anstaett.

Investigators say the attacker appears to be a white male in his mid-20s, weighing 180 to 220 pounds and is 5 feet 9 inches to 6 feet 2 inches tall.

In each Lawrence rape, the attacker has been armed, but police haven't given other details, such as how he entered the home, what he wore or how he chose his victims. In the Manhattan cases, the attacker broke into the women's homes while they slept. He covered his forearms with dark clothing, used gloves and wore boots.

Six announced the possible connections in a written statement that also advised residents to be vigilant during spring break next week. He noted that when universities are not in session, apartments and other student housing areas may be targeted by criminals.

"We're encouraging Kansans to take extra safety precautions and report any suspicious activity to local law enforcement immediately," he said.

Lawrence police spokesman Bill Cory said information about the rapes has residents paying more attention to their surroundings.

"I believe the community's concerned. Everyone's concerned when you have a crime like this," Cory said.

Information has been distributed to students at both campuses, including a Feb. 26 newsletter at Kansas State that mentioned the "so-called `serial rapist"' and offered general information about sexual assaults.

Mary Todd, director of the Kansas State Women's Center, said the campus has conducted a number of outreach drives to get information to students.

Todd said that women on campus have expressed concern about the spate of rapes. Some are now living with roommates when they would prefer to live alone, she said.

"The loss of freedom to take a walk, to photograph the lake in the evening, to watch a sunrise from the park, to go get a bite during late night studying, these sorts of things are lost to many women, who now have a different experience in college than most male students or than those in an earlier generation," Todd said.

Jill Jess, spokeswoman for the University of Kansas, said that college's students would be getting an e-mail later this week urging them to be cautious while away from school.

"There is an awareness, but I wouldn't say that anyone's in a state of panic," Jess said.

The University of Kansas has about 25,000 students at the Lawrence campus, while Kansas State has about 21,000 students at its Manhattan campus.