A University of Texas fraternity is under investigation following complaints about how Hispanics were portrayed during a weekend party, university officials said Tuesday.

At least nine complaints about the Phi Gamma Delta party's "culture, costumes and construction-worker scenario" were filed with the university's division of diversity and community engagement, said Erica Saenz, the office's associate vice president.

The Office of the Dean of Students also is investigating. The dean, Soncia Reagins-Lilly, said the office is looking into "whether or not it was freedom of speech, whether or not it was hate, whether or not it was a violation (of school rules)." If a violation of school rules did occur, the fraternity could face sanctions, she said.

The university newspaper, the Daily Texan, reported that guests wore sombreros, ponchos, construction worker outfits and military gear. Texas Fiji was established in Texas in 1883, making it one of the oldest fraternities at the school. The party took place at the fraternity's house on the north end of campus.

Fraternity president Andrew Campbell told the newspaper the party was western-themed and apologized for "any insensitivity that our guests or members may have portrayed." Campbell could not be reached for comment Tuesday by The Associated Press.

"At our university, we actively work on creating an environment that is inclusive and welcoming to all students," Saenz said, adding that parties like the one under investigation "go against the work we do in this area, and certainly go against the university."

Complaints filed with Saenz's office will be investigated by the Campus Climate Response Team, which is not a disciplinary body but provides education, conducts outreach and offers support for campus organizations. Saenz's department found that 670 bias complaints were filed about events during the 2013-2014 school year, though most concerned events held the Young Conservatives of Texas.