Two carnival revellers masquerade as Leonardo da Vinci's painting “Mona Lisa” pose in St. Mark's Square in Venice, Italy, Sunday, January 31, 2016. Carnival-goers in Venice are being asked by police to momentarily lift their masks as part of new anti-terrorism measures for the annual festivities. (Photo by Domenico Stinellis/AP Photo)

South Korean rescue members wearing chemical protective suits walk past a monster character (R) during an anti-terror drill as part of a disaster management exercise at the COEX shopping and exhibition center in Seoul on May 20, 2016. South Korea is holding its 2016 Safe Korea anti-disaster exercise this week against terrorist threats and natural disasters. (Photo by Jung Yeon-Je/AFP Photo)

An Iraqi special forces Counter Terrorism Service (CTS) member screams during a battle against Islamic State group jihadists (IS) in Mosul's al-Rifaq neighbourhood on January 8, 2017, as an ongoing military operation against the militants continues. Elite Iraqi forces battling the Islamic State group in eastern Mosul reached the Tigris River that splits the city in two for the first time, a spokesman said. (Photo by Dimitar Dilkoff/AFP Photo)

A woman walks past as South Korean soldiers participate in an anti-chemical and anti-terror exercise as part of the 2023 Ulchi Freedom Shield (UFS) at subway station on August 22, 2023 in Seoul, South Korea. The 11-day exercise, which features drills including the handling of chemical and biological attacks, is a regular joint exercise between U.S. and South Korean troops. (Photo by Chung Sung-Jun/Getty Images)

A Russian Rosguardia (National Guard) servicemen secures an area as a massive blaze seen over the Crocus City Hall on the western edge of Moscow, Russia, Friday, March 22, 2024. Several gunmen have burst into a big concert hall in Moscow and fired automatic weapons at the crowd, injuring an unspecified number of people and setting a massive blaze in an apparent terror attack days after President Vladimir Putin cemented his grip on the country in a highly orchestrated electoral landslide. (Photo by Dmitry Serebryakov/AP Photo)

A Togolese policeman, disguised as a terrorist, brandishes his weapon on October 20, 2022 during an anti-terrorism exercise at the Peacekeeping Operations Training Center (CEOMP). Togo's military on Thursday carried out a simulated jihadist attack in the capital Lome on Thursday, practising countering an assault and hostage-taking at a restaurant. Togo and neighbouring West African coastal states like Ghana and Benin are preparing for growing spillover from jihadist conflicts across their northern borders in Niger and Burkina Faso. (Photo by Yanick Folly/AFP Photo)

A couple walk in the Retiro park in Madrid on November 17, 2020 as a thick fog falls on the Spanish capital. (Photo by Gabriel Bouys/AFP Photo)

A mannequin stands in a textile factory in Madrid, Spain May 19, 2014. (Photo by Andrea Comas/Reuters)