A 14-year-old girl tweeted a terror threat at American Airlines, later claiming that it was a "joke." Police in Rotterdam reportedly arrested the Dutch girl in relation to the threat, local media said.

The airline responded to the teenager, identified by her first name, Sarah, after she pretended to be an al-Qaeda member from Afghanistan.

She tweeted: "@AmericanAir hello my name's Ibrahim and I'm from Afghanistan. I'm part of Al Qaida and on June 1st I'm gonna do something really big bye."

Six minutes after the tweet, they responded: "@queendemetriax_ Sarah, we take these threats very seriously. Your IP address and details will be forwarded to security and the FBI."

The airlines' 800,000 or more followers picked up on the conversation, at which point Sarah immediately started apologizing.

"omfg I was kidding," she tweeted, adding: "I'm so sorry I'm scared now" and "I was joking and it was my friend not me, take her IP address not mine."

The Dutch native received violent messages from the Twitterverse after her tweet, which has been shared thousands of times. Users accused her of being "immature" and racist."

Even after clarifying that she was from the Netherlands and not Afghanistan, Sarah was detained "after Rotterdam police's own investigation," not at the request of American Airlines or the FBI.

"At American, the safety of our passengers and crew is our number one priority," the company said, according to the New York Daily News. "We take security matters very seriously and work with authorities on a case by case basis."

The original message and American Airlines' reply have since been taken down from the site.

"We took it down basically because it generated a lot of traffic. We took it down so we could better focus on our customers," they said.