Two Dutch YouTubers in the US with the hope of attending the viral Storm Area 51 Facebook event were arrested near the famous US Air Force site.

The Nye County Sheriff's Office said Ties Granzier, 20, and Govert Sweep, 21, were caught trespassing at the Nevada National Security Site, a government nuclear testing facility close to Area 51, on Tuesday.

Police said the pair told them they could read and speak English perfectly, but chose to ignore "No Trespassing" signs on the site.

More than two million people have clicked attending on the "Storm Area 51" Facebook event scheduled for September 20, which has the jokey rallying cry: "Let's see them aliens."

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Two Dutch YouTubers visiting Nevada intending to attend the viral "Storm Area 51" Facebook event were arrested after allegedly trespassing at a government site close to the secret facility.

Police officers were called to the Nevada National Security Site — a government nuclear facility 10 miles from Area 51 — on Tuesday after two men were seen inside the perimeter, the Nye County Sheriff's Office said in a statement.

Deputies identified the pair on Wednesday as Ties Granzier, 20, and Govert Sweep, 21. They are both YouTubers from the Netherlands.

The Nye County Sheriff's Office said they found a parked car belonging to the pair three miles inside the Nevada National Security Site. The car contained a laptop, camera, and a drone.

Deputies examined the camera, finding footage shot inside the facility, and subsequently arrested the pair on trespassing charges.

A sign at the perimeter of the Nevada National Security Site. Nye County Sheriff's Office

Trespassing at a military base can be punished with six months imprisonment, a $500 fine, or both, according to the US Department of Justice.

Read more: Guy Fieri joked that he's going to bring 'radioactive ribs' for the people planning to 'storm' Area 51

Officials said the duo had flown to the US especially for the "Storm Area 51, They Can't Stop All of US" Facebook event on September 20.

The event, set up in June, urges conspiracy theorists to break into the Nevada Test and Training Range, known commonly as Area 51, in an attempt to "see them aliens," a joke based around a conspiracy theory that the government keeps aliens there.

Approaching Area 51. Laura Rauch/AP Photo

Read more: There's now an event encouraging people to 'storm' the Bermuda Triangle and more than 40,000 people have signed up

Organizers have said the event is a joke, but it has gained momentum, with two million people clicking attending and authorities expecting a large number of people to actually show up.

Granzier posted a photo of the Grand Canyon on Instagram on Tuesday, with the caption: "It has always been a dream to be here, now to crazy recordings of crazy adventures and ... area 51 ..."

the grand mother of canyon en de hoover dam 😎 toch wel altijd al een droom om hier te zijn 🗺 nu door naar gekke opnames van gekke avontuurtjs en... area 51... 👽 A post shared by TIES (@ties) on Sep 10, 2019 at 9:12am PDT Sep 10, 2019 at 9:12am PDT

Police said that Granzier and Sweep told them they understand English perfectly, but had decided to ignore the "No Trespassing" signs at the government facility.

Insider contacted representatives for both Sweep and Granzier for comment, but is yet to receive a response.

Granzier has 735,000 subscribers on his YouTube channel and Sweep more than 300,000.

Despite the jovial nature of the Facebook event, the US Air Force issued a warning to those travelling to the Nevada Test and Training Range on September 20.

"The US Air Force is aware of the Facebook post," Air Force spokesman Maj. Ethan Stroker told Insider. "Any attempt to illegally access military installations or military training areas is dangerous."

Read more: 'No little green men here': How Area 51 became associated with UFO and alien sightings

Area 51 has long been regarded by conspiracy theorists as a repository for the government's knowledge about extraterrestrials and UFOs.

It was confirmed as an Air Force base in 2013.

Secrecy around the area was not to keep knowledge of alien life from the US public, but because the base was used to keep government testing of high-flying planes during the Cold War hidden from the USSR.

Area 51's current purpose is unknown.