Police officers detain an opposition protester during a May Day rally in Saint Petersburg, Russia on May 1, 2019. Labor Day or May Day is observed all over the world on the first day of the month of May to celebrate the economic and social achievements of workers and fight for laborers rights. (Photo by Igor Russak/Reuters)

Nice's Youcef Atal, left, and PSG's Juan Bernat challenge for the ball during the French League One soccer match between Paris Saint-Germain and Nice at the Parc des Princes stadium in Paris, France, Saturday, May 4, 2019. (Photo by Christophe Ena/AP Photo)

A Vietnamese cosplayer poses as police officer character from the game during the League of Legends (LOL) Mid-Season Invitational 2019 play-in group stage, in GG Stadium, Ho Chi Minh, Vietnam May 5, 2019. (Photo by Reuters/Kham)

An abandoned protection masks in the deserted building near bypass channel for cooling at the Chernobyl nuclear power plant in the Exclusion Zone, Ukraine, April 5, 20177. The Chernobyl nuclear accident occurred on 26 April 1986 in the No.4 light water graphite moderated reactor at the Chernobyl Nuclear Power Plant near Pripyat. An estimated 47,000 people of the city of Pripyat were evacuated after the explosion in 1986. (Photo by Vitaliy Holovin/Corbis via Getty images)

This photo taken on May 17, 2019 shows rough rubies displayed at the gems market in Mogok town, north of Mandalay. Burrowing deep underground, thousands of informal miners risk their lives to find gleaming red gems as a law change spurs opportunity in Myanmar's “land of rubies”. (Photo by Ye Aung Thu/AFP Photo)

A Chinese ethnic Lisu honey hunter holds a large piece of wax from a hive while gathering wild cliff honey in a gorge on May 10, 2019 near Mangshi, in Dehong prefecture, Yunnan province China. (Photo by Kevin Frayer/Getty Images)

Iranian women sit in a bus in the capital Tehran on June 25, 2019. Iran's President Hassan Rouhani said today that new US sanctions against senior Iranian officials including top diplomat Mohammad Javad Zarif showed Washington is “lying” about an offer to negotiate. (Photo by Atta Kenare/AFP Photo)

People wear clothing to protect them from the heat while riding along a street in Hanoi, Vietnam, 24 April 2019. North and central Vietnam was recently affected by extreme hot weather, with the highest temperatures reaching over 40 degrees Celcius, according to the National Centre for Hydro-meteorological Forecasting. (Photo by Luong Thai Linh/EPA/EFE)