Trainees of the Tianjiao Special Guard/Security Consultant bodyguard training camp watch their instructor use a scarf to cover a student's head during a demonstration of close-quarter combat skills at a special course on flight safety inside a scale model of a passenger jet at a flight attendant training centre on the outskirts of Beijing, March 18, 2014. Inspired by the missing Malaysia Airlines Flight MH370, the company wanted to emphasize the importance of aviation safety by teaching their trainees emergency evacuation procedures and close-quarter combat skills to handle situations such as natural disasters and plane hijacks, according to the company. (Photo by Jason Lee/Reuters)

A protestor confronts police and National Guard troops near the Wauwatosa City Hal on October 09, 2020 in Wauwatosa, Wisconsin. The city has faced three days of demonstrations, prompting a 7 PM curfew, after District Attorney John Chisholm refused to press charges against Wauwatosa Police Officer Joseph Mensah for the Feb. 2 fatal shooting of 17-year-old Alvin Cole. (Photo by Scott Olson/Getty Images)

Ukrainian servicemen of the State Border Guard Service wait for an order to move to the mortar position at the entrance of the shelter in Bakhmut on February 16, 2023, as the head of Russia's mercenary outfit Wagner said it could take months to capture the embattled Ukraine city and slammed Moscow's “monstrous bureaucracy” for slowing military gains. (Photo by Yasuyoshi Chiba/AFP Photo)

Jordanian policewomen train in unarmed combat in the training city August 21, 2008 in Muwaqqar, east of Amman, Jordan. A women's police academy opened in Amman in 1972 making Jordan the first Arab country to admit women to its police services. Jordanian policewomen work as personalities' guards, special security operations and traffic policewomen including motorcycling among other professions. (Photo by Salah Malkawi/Getty Images)

West German police arrest a young man, one of the angry crowd throwing stones at a bus full of Soviet guards making their way to the Soviet War Memorial, 20th August 1962. The crowd were incensed by the death of 18-year-old Peter Fechter, who was shot while trying to cross the Berlin Wall a few days earlier. (Photo by Central Press/Hulton Archive/Getty Images)

Chinese archaeologists announced the discovery of 110 life-sized terracotta warriors, guarding the tomb of Qin Shi Huang, China's first emperor.

Photo: Archaeologists work on a terracotta warrior in the third excavation of pit one at the Terracotta Warriors and Horses Museum in Xi'an in northwest China's Shaanxi province Saturday, June 9, 2012. (Photo by AP)

Members of the 3rd U.S. Infantry Regiment place American flags at the graves of U.S. soldiers buried at Arlington National Cemetery in preparation for Memorial Day May 26, 2011 in Arlington, Virginia. “Flags-In” has become an annual event since the 3rd U.S. Infantry Regiment (The Old Guard) was appointed an Army official ceremonial unit in 1948. Every available soldier in the 3rd U.S. Infantry Regiment participates in these annual ceremonies. (Photo by Win McNamee/Getty Images)

A boat, center, is surrounded by Japan Cost Guard's patrol boats after some activists descended from the boat on Uotsuri Island, one of the islands of Senkaku in Japanese and Diaoyu in Chinese, in East China Sea Wednesday, Aug. 15, 2012. Regional tensions flared on the emotional anniversary of Japan's World War II surrender as activists from China and South Korea used Wednesday's occasion to press rival territorial claims, prompting 14 arrests by Japanese authorities. The 14 people had traveled by boat from Hong Kong to the disputed islands controlled by Japan but also claimed by China and Taiwan. (Photo by Yomiuri Shimbun/Masataka Morita/AP Photo)