The NBC News Twitter feed was hacked on Friday by a group that claimed a hijacked plane, in a fresh attack, had crashed into the site where New York's twin towers were destroyed in September 11 attacks 10 years ago.
The hoax by a group called The Script Kiddies came just two days before the United States marks the 10th anniversary of the 2001 attacks on New York's World Trade Center and the Pentagon in Washington.
"The NBC News twitter account was hacked late this afternoon and as a result, false reports of a plane attack on ground zero were sent to @NBCNews followers," NBC said in a statement.
"We are working with Twitter to correct the situation and sincerely apologize for the scare that could have been caused by such a reckless and irresponsible act," the network added.
The Twitter account was later suspended, but according to screen shots of the fake tweets, three messages were sent in quick succession.
"Breaking News! Ground Zero has just been attacked. Flight 5736 has crashed into the site, suspected hijacking. more as the story develops," read the first. The Script Kiddies claimed responsibility in a later tweet.
New York and Washington D.C. are already on high alert in response to a credible but unconfirmed threat of an al Qaeda plot to target the cities on the anniversary of the downing of the World Trade Center towers by hijacked airplanes.
The hacking of the NBC News Twitter account was met with instant condemnation. The Business Insider called it a "disgusting 9/11 prank", while Washington Post blogger Melissa Bell said the tweets seemed "particularly shocking and cruel."