A Facebook user posted threatening messages on the White House page referencing new terror attacks on September 11.
WNBC in New York grabbed a screen shot of the threatening messages, seen above.
"We'll come back U.S.A. One day only 11/9/2011," reads one message, featuring a photo of Osama bin Laden, using the date/month formula to reference Sept. 11.
"We'll come to u white house sooooooooooon," says another.
"We'll come back 11/9/2011 to kill u all," a third posting says.
But a senior counter-terrorist official told NBC News on Sunday afternoon about the possibility of any imminent terror attack on the country - "We are still at the same place we were three days ago: credible, specific, and uncorroborated."
Investigators have chased a tip that al-Qaida may have sent three men to the U.S. on a mission to detonate a car bomb in either Washington or New York. But officials have said they've found no evidence al-Qaida has sneaked anyone into the country.
Counterterrorism adviser John Brennan said officials are ``looking at travel data, other types
of pieces of information and trying to correlate them against that
reporting that has come in.''
``It's not confirmed but we are not relaxing at all,'' he said. ``This is a 24/7, round-the-clock effort by all elements of the U.S. counterterrorism community both here in the United States as
well as abroad.''
The terror network has long sought to attack the U.S. again and several plots have previously been thwarted. U.S. Navy SEALs killed al-Qaida leader Osama bin Laden in a May raid at his compound in the Pakistani city of Abbottabad.