A US public relations executive has lost her job with the media company IAC, after tweeting a racist message about Aids in Africa.

Justine Sacco provoked an internet storm when she tweeted: "Going to Africa. Hope I don't get AIDS. Just kidding. I'm white."

Ms Sacco has now apologised for the comment, saying: "Words cannot express how sorry I am."

She added that she was ashamed "for being insensitive" about Aids.

IAC issued a statement on Saturday evening saying that the company and Ms Sacco had "parted ways".

#HasJustineLandedYet

Ms Sacco posted her controversial tweet as she boarded an 11-hour flight to South Africa.

She was on the plane as the storm about the tweet gathered pace, with the hashtags #JustineSacco and #HasJustineLandedYet trending on twitter and fake accounts being created in her name.

She has now sent a statement to ABC News in the US - and reportedly to South African newspaper The Star as well - saying of South Africa: "This is my father's country, and I was born here. I cherish my ties to South Africa and my frequent visits, but I am in anguish knowing that my remarks have caused pain to so many people here; my family, friends and fellow South Africans.

"I am very sorry for the pain I caused," she added.

In its own statement about the tweet, the IAC said: "The offensive comment does not reflect the views and values of IAC. We take this issue very seriously, and we have parted ways with the employee in question."

It said there was "no excuse for the hateful statements that have been made".

But the company added that it hoped "time and action, and the forgiving human spirit, will not result in the wholesale condemnation of an individual who we have otherwise known to be a decent person at core."

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