A false report of explosions at the White House and injuries to President Barack Obama sent U.S. stocks plunging Tuesday before they recovered quickly.
The Associated Press said hackers broke into its Twitter account and wrote: "Breaking: Two explosions in the White House and Barack Obama is injured."
Within minutes, the most widely watched U.S. stock index, the Dow Jones Industrial Average, fell about 130 points, erasing the day's gains.
But the Dow regained the losses just as quickly when it became obvious the reports were a hoax.
A group called the Syrian Electronic Army is claiming responsibility for the cyber attack. Its claim has not been verified.
The group has claimed similar attacks on other news organizations.