Police departments across the US are seeing a huge increase in "SWATting", a prank where an anonymous tip-off tricks a police department to go to a particular person's address in response to a fake violent situation, such as a shooting spree.

Yesterday in Littleton, Colorado, professional Counter-Strike gamer Jordan Mathewson (known by the username "Kootra" online) was live-streaming a game on Twitch when an fully-armed SWAT team burst into the office building he was in and arrested him, according to Denver local TV channel KMGH-TV 7News.

"The caller claimed to have shot two co-workers, held others hostage, and threatened to shoot them. He stated that if the officers entered he would shoot them as well," the Littleton Police Department said in a statement on Wednesday afternoon.

"There were no victims or any evidence that a shooting had taken place. If the investigation determines that today's incident was a hoax, those involved will be prosecuted to the fullest extent of the law."

During the incident, several schools in Littleton were put on lockdown, and employees from several office buildings were being evacuated in small groups, some with their hands raised, photos seen by 7News showed.

The scene of the prank may be considered particularly unfortunate given Littleton was the scene of one of the world's most infamous school shootings 15 years ago. Teenagers, Eric Harris and Dylan Klebold opened fire in Columbine high school, killing 13 people.

Pranking live-streamers on Twitch

Twitch is a dedicated gaming community website where gamers can broadcast live gameplay footage recorded from their PC, Mac or games consoles like the PlayStation 3, PlayStation 4 and Xbox 360, together with live webcam footage of their reactions, and professionals can earn money from getting viewers to subscribe to watch them play in real-time.

Mathewson is the founder and a member of The Creatures Twitch channel, an online business which is headquartered in an office complex in Littleton.

The channel is currently offline, and in a YouTube video posted by a viewer who was watching the stream at the time of the raid, Mathewson can be seen being searched and then handcuffed to a chair.

"That's streaming right now," Mathewson tells the police officer in the video, nodding towards the webcam and PC.

"That's streaming? So tell us, why are we here today?" a police officer asks Mathewson.

"I'm streaming right now, this is our business. So I'm sitting here, playing a game and people are watching it, and I guess a joker thought it would be funny to call you guys in," Mathewson explains to the police.

Rise in SWATting pranks

Shortly afterwards a police officer disables the webcam and Mathewson can be heard on the microphone instructing the police how to turn the live stream on the PC off.

According to The Creatures' subreddit page on social bookmarking site Reddit, other employees at Creature were also arrested by the police, but everyone including Mathewson has now been released. The police also confirmed that they found fake "simulated weapon" gun props in the office during the raid.

The police said that the 911 call was made from a landline. A rival gamer who goes by the online handle @screwpain has claimed responsibility on Twitter, and he confirmed that he had been arrested, several hours after exchanging tweets with 7News:

Last year, a spate of celebrities were visited by police SWAT teams following hoax calls, including Tom Cruise, Kim Kardashian, Clint Eastwood, Chris Brown, Paris Hilton, Selena Gomez, Justin Timberlake, Russell Brand, Justin Bieber, Ashton Kutcher and Rihanna.

Although the phrase "SWATting" has been used by the FBI since 2008, the pranks seem to have been escalating in the last 18 months, to the extent that after April 2013, the LA police department stopped publishing reports of these incidents to try to prevent copycats.