A woman smokes a cigarette next to man wearing a mask during lunch hour at the central business district in Singapore September 29, 2015. The 3-hour haze Pollutant Standards Index (PSI) reached a high of 173 at 8am on Tuesday, according to the National Environment Agency. Slash-and-burn agriculture in neighboring Indonesia has blanketed Singapore in a choking haze for weeks. (Photo by Edgar Su/Reuters)

Demonstrators wear masks depicting Brazil's former president Luiz Inacio Lula da Silva (R) and Brazil's President Dilma Rousseff (L) as they take part in a protest calling for the impeachment of Rousseff at Paulista Avenue in Sao Paulo, Brazil, December 13, 2015. (Photo by Nacho Doce/Reuters)

Matachines dancers participate in a religious festival in Saltillo, Mexico, April 17, 2016. Matachines dancing is a masked dance introduced by Spanish missionaries, and has been adopted by cultures from Peru to northern Mexico. It is performed to show respect to Mother Mary or the Guadalupe Virgin, a saint, or to simply worship God. (Photo by Daniel Becerril/Reuters)

A masked Bulgarian dancer takes part in the second competition day of the 24th International Festival of Masquerade Games “Surva” in the town of Pernik, Bulgaria Saturday, January 31, 2015. Some 5,000 people are expected to take part in the three-day festival devoted to an ancient Bulgarian pagan rite. Surva is performed by costumed men, some in sheepskin, or other colorful garments, bells and masks, who walk around and dance to scare away the evil spirits, in hope to provide a good harvest, health, fertility, and happiness. (Photo by Valentina Petrova/AP Photo)

Masked penitents holds their crosses during spring “Romeria Cruceros de Arce”, in Roncesvalles, northern Spain, Sunday, May 10, 2015. Every year on the second Sunday in spring, people with crosses march from their small Pyrenees towns to Roncesvalles Church in tribute of the Virgin. (Photo by Alvaro Barrientos/AP Photo)

A participant wearing a tiger mask performs during the “Paseo del Pendon”, a traditional artistic march in Chilpancingo, December 21, 2014. The “Paseo del Pendon” (walk banner) is a traditional celebration in the streets of Chilpancingo to mark the begin of the the year-end festivities in the city. (Photo by Jorge Dan Lopez/Reuters)

Masked youths face off with French police and gendarmes during a demonstration in Paris as part of nationwide protests against plans to reform French labour laws, France, June 14, 2016. (Photo by Willi Effenberger/Pacific Press/SIPA Press)

A masked protester talks to a soldier during clashes after the funeral of Brig. Gen. Wissam al-Hassan October 21, 2012. Lebanese soldiers fired guns and tear gas to push back hundreds of protesters who broke through a police cordon and tried to storm the government headquarters in Beirut. (Photo by Hussein Malla/Associated Press)