The false tweet said there had been two explosions at the White House and that President Barack Obama was injured. The attack on AP's Twitter account and the AP Mobile Twitter account was preceded by phishing attempts on AP's corporate network.
The AP confirmed that its Twitter account had been suspended following a hack and said it was working to correct the issue. The fake tweet went out shortly after 1 p.m. and briefly sent the Dow Jones Industrial Average sharply lower. The Dow fell about 143 points, from 14,697 to 14,554, after the fake Twitter posting, and then quickly recovered.
A Securities and Exchange Commission spokeswoman declined comment on the incident.
AP spokesman Paul Colford said the news cooperative is working with Twitter to investigate the issue. The AP has disabled its other Twitter accounts following the attack, Colford added.
White House spokesman Jay Carney said the President is fine. "I was just with him," Carney said at a news briefing.
A representative for Twitter did not immediately return messages for comment.