Police and school officials are investigating a report of a sexual assault Friday at Free State High School involving a 15-year-old girl.
Police on Tuesday said they had no suspects.
Lawrence public school officials said they were cooperating with police in the investigation and that no extra security precautions were being taken at the school.
In addition to a Lawrence Police officer assigned to the school, Free State has three security officers.
"We think we do our best to protect the students," school district spokeswoman Julie Boyle said.
The girl's parents called police Saturday to report the alleged assault, Sgt. Mike Pattrick said.
The girl was not physically injured, Pattrick said, and she did not know her attacker.
Police declined to release any other details about the incident, including where the alleged assault took place.
School officials, who were notified over the weekend about the incident, also declined to comment about the assault report other than to emphasize that the "safety of students and staff is the top priority" of the school district, Boyle said.
"The district encourages students to share with their parents or adults at school any information that they may have that is relevant to school safety," Boyle said.
Anyone with information about the incident is asked to call Douglas County Crime Stoppers at 843-TIPS. Callers to the hot line can remain anonymous.