The Onion, a satirical news Web site and newspaper known for its ability to elicit peals of laughter, isn’t getting too many guffaws on this one. The site tweeted Thursday:

The site also posted the news to its Facebook page.

Twitter users immediately responded by asking whether this was a joke or if the site had been hacked. In recent months, hackers known as the Script Kiddies have hacked the Twitter accounts of Fox News, Wal-Mart, Unilever, Pfizer and NBC News, often posting fake news with “BREAKING” at the front.

The Onion office in New York confirmed that the tweet was not a hack, saying: “This is satire. That’s how it works.”

In Washington, people didn’t find the tweet so funny. One person wrote, “I work at the Capitol and I just yelled at my coworkers that there was gunfire... you scared the [expletive] out of me #fakenewsscares.”

Another Twitter user wrote, “I mean, I know you guys do satire, but I really don't get this one....”

The Onion’s tweets were connected to a story posted on their Web site Thursday, in which Congress takes a group of schoolchildren hostage and demands $12 trillion in cash, satirizing the recent budget debacles in Washington.

Update, 11:42 a.m.

The Washington Post’s Federal Eye blogger Ed O’Keefe reports that Capitol Police have reacted “angrily” to the parody.

In a statement released to reporters, police said, “Conditions at the U.S. Capitol are currently normal... There is no credibility to these stories or the twitter feeds.”

Update, 12:31 a.m.

The Onion has kept the joke going, tweeting absurdities like “Arlington gun shop confirms Rep. Eric Cantor bought six semi-automatic handguns, three rifles and 600 clips of ammo last month #CongressHostage.”

The site has also put up a video that shows children calling for their “mommy” as politicians hold them hostage.

On Twitter and Facebook, much of the reaction is now shifting from panic to mockery of the panicked.

Journalist Josh Wolf compared the response to the Onion’s tweets to the Orson Welles War of the Worlds radio drama, which caused panic for listeners who thought the simulated narration of Martians attacking the world was real.

D.C.-based photographer Dave Stroup tweeted: “Not sure what's worse, people not knowing the Onion is fake, or that it seemed believable that Members of Congress would take kids hostage.”