US Edition 
'Bogus' AP tweet about explosion at the White House wipes billions off US markets
The FBI and SEC are to launch investigations after more than £90bn was temporarily wiped off the US stock market when hackers broke into the Twitter account of the Associated Press and announced that two bombs had exploded at the White House, injuring Barack Obama.
“Breaking: Two Explosions in the White House and Barack Obama is injured,” said the fake “alert” from one of America’s most trusted news sources, briefly fooling some news outlets and sending the Dow Jones plunging 145 points in the space of two minutes — or 1pc.
The benchmark S&P 500 index also fell nearly 1pc in the space of three minutes as the tweet hit the markets. With the S&P valued at roughly $14.6 trillion at the moment of the false tweet, that three-minute plunge briefly wiped out $136.5bn (£92.2bn) of the index's value, according to Reuters.
A screengrab of the fake tweet sent by hackers from the Associated Press Twitter account
SEC Commissioner Daniel Gallagher said: "You can rest assured we're looking into it. I can't tell you exactly what the facts are at this point or what we're looking for, but for sure, we want to understand major swings like that, however short it was."
The losses were rapidly recovered as it became clear that it was a false alarm, but coming just over a week after the bombing of the Boston marathon it took several minutes before it became clear it was malicious cyber mischief-making.
Russia Today was one of the few outlets that fell for it, re-tweeting the post and adding “More to come”, but later deleting the tweet.
In Washington, the AP’s chief White House correspondent Julie Pace was forced to interrupt the daily briefing in the White House press room to confirm what everyone in the room already knew.
“It appears as though AP’s Twitter account has been attacked,” she said, “so anything that was just sent out is obviously false.”
Jay Carney, the White House press secretary, added: “I appreciate that. And I can say that the president is fine, I was just with him.”
Responsibility for the attack was claimed by the Syria Electronic Army, a group that is reported to have the tacit support of Bashar al-Assad, although that could not be independently confirmed.
The confusion quickly spawned a round of Twitter jokes comprising unlikely news events under the hashtag #APTweets. “Commercial flying experience now viewed as ‘pleasing’,” said one, in an ever lengthening series.
Other jokes focused on the failures of some US 24-hour rolling news networks when covering Boston bombings last week, including the disastrous decision by CNN’s John King’s to report that a suspect was in custody for the bombings — only to have to retract the report within the hour.
“Are you sure you didn’t just hire CNN’s reporters to cover your Twitter feed?”, asked one Facebook user on AP’s official page, which was used to confirm that the Twitter account had been temporarily suspended.
Later, satirical news website The Onion gave its own spin on the incident by tweeting the bogus tweet word for word, but under its own handle.
Associated Press journalist Mike Baker wrote on his Twitter account: "The @AP hack came less than an hour after some of us received an impressively disguised phishing email".
AP said the incident came after hackers made repeated attempts to steal the passwords of AP journalists.
The agency also said that its mobile Twitter account, @AP_Mobile, had similarly been hacked.
A spokesman stated that all AP Twitter accounts are to be suspended "until we can be assured of their security", and warned that followers should not respond to news posted by the accounts.
The cyberattack is the latest in a string targeting international media organisations, including the New York Times and the Wall Street Journal.