Mount Sinabung, a highly active volcano on Sumatra island, erupted several times this week. A volcanology agency has declared a danger zone of about four miles from the crater after seven farmers were killed and two others seriously injured. Here: A man carries his dog as a giant ash cloud rises from the Sinabung volcano in Karo, Indonesia on May 26, 2016. (Photo by Sutanta Aditya/Barcroft Images)

Rebel fighters fire towards positions of regime forces in Ramussa on the southwestern edges of Syria's northern city of Aleppo on August 6, 2016. Syrian rebels said they have broken a three-week government siege of second city Aleppo, turning the tables on Russian-backed regime forces who are now on the defensive. (Photo by Fadi Al-Halabi/AFP Photo)

A security man keeps guard during Malawi's President elect Arthur Peter Mutharika swearing in ceremony at Kamuzu Stadium in Blantyre on May 28, 2019, after a contentious election marred by allegations of fraud and vote-rigging. The Malawi Electoral Commission announced on Monday that Mutharika, who heads the ruling Democratic Progressive Party (DPP), had narrowly won last week's vote after an injunction barring the release of the results was lifted. (Photo by Amos Gumulira/AFP Photo)

Britain's Prime Minister Boris Johnson gestures during a visit to Darnford Farm in Banchory near Aberdeen in Scotland on September 6, 2019. Prime Minister Boris Johnson heads to Scotland on Friday in campaign mode despite failing to call an early election after MPs this week thwarted his hardline Brexit strategy. (Photo by Andrew Milligan/Pool via AFP Photo)

In this photo taken October 12, 2019, a spiritual healer known as a “madrina” starts a ritual on Sorte Mountain where followers of indigenous goddess Maria Lionza gather annually in Venezuela's Yaracuy state. While her followers gather on the mountain for weeks at this time of the year, October 12 marks the biggest gathering, coinciding with Indigenous People's Day, known in Latin America as “Dia de la Raza”. (Photo by Ariana Cubillos/AP Photo)

Riot police clash with demonstrators protesting against proposed pension reforms outside the Congress in Buenos Aires on December 18, 2017. Protesters angry at proposed pension and welfare reforms attacked police close to Argentina's congress building in Buenos Aires on Monday, the second protest in a week to turn violent. Activists lobbed stones, bottles and firecrackers at police as huge crowds demonstrated against pension reforms proposed by the center-right government of President Mauricio Macri. (Photo by Eitan Abramovich/AFP Photo)

People cross Flagstaff Hill as the snow starts to fall, in Schenley Park, on their way to the Carnegie Mellon University campus, Tuesday, March 20, 2018, in the Oakland section of Pittsburgh. Yet another powerful storm bore down on the Northeast on Tuesday, with wind-whipped snow falling in parts of Pennsylvania and New Jersey as people grumbled and complained about a first day of spring that looked an awful lot like the last weeks of winter. (Photo by Darrell Sapp/Pittsburgh Post-Gazette via AP Photo)

A man carries a dog and wades through a flooded street in Chennai, in the southern Indian state of Tamil Nadu, Wednesday, December 2, 2015. Weeks of torrential rains have forced the airport in the state capital Chennai to close and have cut off several roads and highways, leaving tens of thousands of people stranded in their homes, government officials said Wednesday. (Photo by AP Photo)