A US public relations executive has provoked a storm of online protest for writing a Twitter comment about Aids in Africa.

Justine Sacco, who works for the media company IAC, wrote: "Going to Africa. Hope I don't get Aids. Just kidding. I'm white!"

Ms Sacco's account has now been deleted.

IAC responded by saying the "outrageous, offensive comment" did not reflect the company's views and values.

"Unfortunately, the employee in question is unreachable on an international flight, but this is a very serious matter and we are taking appropriate action," the IAC said in a statement to the media blog Valleywag.

IAC is the parent company of Match.com, The Daily Beast, Dictionary.com and BlackPeopleMeet.com, a dating site for African-Americans.