An unknown number of guns are being built with the mechanisms, causing problems for the police and ATF officials. Photo: An ATF agent holds a generic unfinished receiver, back, and one that has been manufactured, front, at an ATF field office in Washington, on May 06, 2014. The ATF is trying to crack down on the trade in the makeshift guns by targeting shops and individuals who offer to turn the unfinished receivers into functional pieces for firearms. (Photo by Bill O'Leary/The Washington Post)

Masks of Republican presidential candidate Donald Trump (C) and Joaquin "El Chapo" Guzman (2nd L) are seen at Grupo Rev in the Mexican city of Cuernavaca near Mexico City, October 14, 2015. (Photo by Henry Romero/Reuters)

Abigail Crouse lifts her Thor hammer high after running through Sleeping Beauty's Castle during the Avengers Super Heroes Half Marathon in and around the Disney Parks in Anaheim, California November 16, 2014. Walt Disney Co has moved aggressively into the race business, attracting tens of thousands of runners every year to its marathons, half-marathons and family-friendly races. (Photo by Eugene Garcia/Reuters)

Ralph Mirebs, an urban explorer and photographer in Russia, has revealed extraordinary photos of Soviet space shuttle prototypes gathering dust in an abandoned hangar. The abandoned hangar is located at the Baikonur Cosmodrome in Kazakhstan, which is still in operation today (with the close of NASA’s shuttle program, Russian Soyuz shuttles are the only way for astronauts to reach the International Space Station). The Buran prototype shuttles found by Mirebs, however, are from an earlier era – they are the last remnants of a space program that began in 1974 and was finally shuttered in 1993. (Photo by Ralph Mirebs/Exclusivepix Media)

A Buddhist monk uses a traditional needle to tattoo the body of a man at Wat Bang Phra in Nakhon Pathom province on the outskirts of Bangkok, Thailand, March 18, 2016. Believers from across Thailand travel to the monastery to have their bodies adorned with tattoos and to pay their respects to the temple's master tattooist. They believe the tattoos have mystical powers, ward off bad luck and protect them from harm. (Photo by Chaiwat Subprasom/Reuters)

A sand carver works on a sculpture during the Sand Sculpture Festival “Dreams” in Ostend, Belgium on June 18, 2019. (Photo by Yves Herman/Reuters)

A huge atlas moth, with a wingspan of more than 9in, photographed on an areca nut plantation in Sirsi, India. (Photo by Uday Hegde/Close Up Photographer of the Year)

A few Catholic devotees manage to get closer to either kiss or rub with towels the cross of the image of the Black Nazarene as they take part in a raucous procession to celebrate its feast day in Manila, Philippines, Saturday, January 9, 2016. As in the past, the annual procession attracts thousands of devotees with scores being injured and saw the deployment of hundreds of police and soldiers. (Photo by Bullit Marquez/AP Photo)