Police say they do not have any leads following the discovery of swastikas drawn on the steps of a Yale University dormitory.

The swastikas were discovered early Sunday morning. The Yale Police Department was continuing to actively investigate the case on Tuesday, but had no leads and had not received any tips as to who may have drawn the swastikas in chalk on the steps, the Yale Daily News reported.

Following the discovery of the swastikas, Yale students gathered outside the dorm to write messages of support for the Jewish community as part of a chalk mural.

It is the second incident in a month. In September, two swastikas were discovered drawn on a whiteboard in a lecture hall.

“I condemn this shameful defacement, perpetrated anonymously under cover of night,” Yale College Dean Jonathan Holloway wrote Monday evening in an e-mail to the campus community. “There is no room for hate in this house.”

“The use of the swastika violates our values of respect, thoughtfulness, generosity, and goodwill. I will not stand idly by when this or other symbols of hate are used on this campus. It is my hope that you will join me in taking a similar stand,” he wrote.

Sunday’s incident comes after several incidents of swastikas drawn on campuses, including Emory University and Eastern Michigan University.

Also this week a swastika was chemically burned into the front yard of a home in a western suburb of Cleveland.