A party held by students in the US, in which at least one person was pictured wearing black face paint, is being investigated by their university.
The party has angered many Clemson students
The South Carolina institution launched the inquiry after talks with students who were angered by the event.
The Clemson University head said he was appalled by the party which appeared to "mock and disparage African Americans".
In an unsigned letter of apology, the party organisers said they had "never meant any racial harm".
"We invited all races and types of people... We want everyone to know how sorry we are, and that we are willing to do anything to make things right," the letter quoted by the Associated Press said.
The party - themed "Living the dream" - was held on 14 January, during Martin Luther King weekend.
Clemson officials are said to have learned of the off-campus event this weekend, after pictures were posted on a social networking website.
The pictures show at least one party-goer with black face paint. One of the girls in the photos has padding in her trousers to make her bottom look bigger.
"Many people have been offended and deeply hurt," university president James Barker said.
Clemson student Ranneice McDonald was quoted by local broadcaster WYFF4 as saying she was "hurt that there were people who think it's okay".
"People painted themselves black. Put fake butts inside their pants to signify the big booty black girl thing. Fake gold teeth in their mouths, caps and jerseys - depicted us wearing such things as that are disgusting to me...
"It makes me sick to my stomach," she said.
One unnamed party organiser told WWFY4 they had decided to have a "gangsta" party.
"You know, the gangsta's like the hip hop culture. So we dressed up. We didn't know it would offend so many people.
"We feel so bad about it. We realise we can't begin to apologise to all the people we offended," the organiser said.
The National Association for the Advancement of Colored People (NAACP) said it was also looking into the party and other similar events reported to have taken place at other colleges in the US.