(NBC) -- Police in Austin, Texas are investigating a series of attacks against minority students at the University of Texas.
The Austin Police Department confirmed Tuesday that three of the cases involved bleach-filled water balloons being thrown or dropped on students.
Reports state that the first incident happened in June, followed by another on August 15, then again on September 18.
Chief Robert Dahlstrom, UT Chief of Police, said they didn't know about any bleach balloon incidents because no student ever filled a report, only when they received calls from the community asking why nothing has been done, did they look into it.
"Through Facebook postings, didn't have any particular names on it, particular location, times or anything specific, so we reached out to students, " Chief Dahlstrom said.
Several weeks ago a fraternity canceled an event because of racism accusation.
The campus newspaper, The Daily Texan, reported the party plans involved someone building a fake Rio Grande and having students dress up in ponchos crossing the river.
This outraged some students, but others said it was not meant to be racist.
"I though it was innocent fun because a lot of people in the fraternity said they were personally Mexican and didn't find it offensive," said UT student Sarah Alerasol.
Others around campus feel there is tension among races.
"There is an issue of under representation of people of color, " said senior Amalia Hernandez.
UT officials are planning several sit down meetings with the sororities and fraternities to discuss equality.