Fireworks fired by protesters explode over riot police during a demonstration in Bangkok, Thailand, on August 15, 2021. Demonstrators were calling for the resignation of Thailand's Prime Minister Prayut Chan-o-cha over the government's handling of the COVID-19 crisis. #

Iraqi Shiites take part in a mourning ritual during which a cleric retells the story of the seventh-century slaying of Prophet Muhammad's grandson Imam Hussein, ahead of the mourning day of Ashura, in the month of Muharram, in the southern city of Basra, on August 14, 2021. #

Participants march during the Bucharest Pride parade on August 14, 2021, in Bucharest, Romania. Thousands attended the annual event, which has been celebrated since 2005, but was suspended in 2020 because of the COVID-19 pandemic. #

Extinction Rebellion activists walk past the Brandenburg Gate as they take part in a protest to demand action against climate change, in Berlin, Germany, on August 16, 2021. #

Members of the religious movement the White Brotherhood perform paneurhythmy, collective meditation movements, on their spiritual new year, on August 19, 2021, on Rila Mountain in Bulgaria. #

Seven-time medalist Jane Blackburn of Team Great Britain participates in a torch-lighting ceremony in the village of Stoke Mandeville in England, on August 19, 2021, as part of a special ceremony prior to the Paralympic Games, due to begin in Tokyo on August 24. #

A U.S. Chinook helicopter flies over the U.S. embassy in Kabul, Afghanistan, on August 15, 2021. Helicopters were landing at the embassy as diplomatic vehicles left the compound during the Taliban advance on the Afghan capital. #

Taliban fighters stand guard in a vehicle along the roadside in Kabul on August 16, 2021, after a stunningly swift end to Afghanistan's 20-year war, as thousands of people mobbed the city's airport trying to flee the group's feared hard-line brand of Islamist rule. #

Young men, who say they deserted the Afghan military and fled to Turkey through Iran, walk in the countryside in Tatvan, in Bitlis province in eastern Turkey, on August 17, 2021. Turkey is concerned about increased migration across the Turkish-Iranian border as Afghans flee the Taliban in their country. #

Houseboats sit in a channel at Lake Oroville State Recreation Area in Butte County, California, on August 14, 2021. At the time of this photo, the reservoir was at 24 percent capacity and 34 percent of its historical average. #

A train sits embedded in mud and debris after flooding in Wald im Pinzgau, near Salzburg, Austria, on August 17, 2021. Storms battered large parts of Austria, causing landslides and flooding. #

Posters using strong language to warn about COVID-19, bearing the marks of the Department of Health and Human Services and the CDC, are on display outside a subway station in New York, on August 17, 2021. This was the first day that New York residents had to show proof of a COVID-19 vaccination to participate in indoor activities. No one has claimed responsibility for the posters, nor has any information been released explaining why they were attributed to the HHS and the CDC. #

An acrobat performs during the Summer Streets event in New York City, on August 14, 2021. The annual event offers entertainment and activities on a seven-mile stretch of city streets from the Upper East Side to the Brooklyn Bridge. #

Indigenous people take part in the commemoration of the 500th anniversary of the fall of the Aztec capital, Tenochtitlán, to the Spanish, at Zocalo square in Mexico City on August 13, 2021. #

A woman takes a picture of a sculpture depicting Puck from Shakespeare's comedy "A Midsummer Night's Dream," during a flower festival in Pakruojis, Lithuania, on August 14, 2021. #

A member of Gladiators NYC, dressed in medieval armor, lies down after fighting in Central Park on August 14, 2021, in New York City. Once a month, Gladiators NYC meets in Central Park for a full-contact-combat tournament. #

Persephone, billed as the world's first robot used as a tour guide inside a cave, guides visitors inside Alistrati Cave, about 135 kilometers (84 miles) northeast of Thessaloniki, Greece, on August 2, 2021. Persephone has been welcoming visitors since mid-July. #