Fighters of the Free Syrian Army fire an anti-aircraft weapon in the rebel-held Mashhad area in southeastern Aleppo, on December 12, 2016, as they battle Syrian government forces during an operation to retake the embattled city. The crucial battle for Aleppo entered its “final phase” after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad. (Photo by AFP Photo/Stringer)

Soldiers are reflected in a puddle during a military parade during the celebrations for Romania's National Day in Bucharest December 1, 2014. (Photo by Radu Sigheti/Reuters)

Afghan firefighters spray water on a U.S. armoured vehicle after a suicide attack on the outskirts of Jalalabad, January 5, 2015. A suicide attacker targeted a U.S. convoy on the outskirts of Jalalabad on Monday but so far no causalities have been reported yet, provincial spokesman Ahmadzia Abdulzai said. (Photo by Reuters/Parwiz)

A view of a Van Gogh-inspired hot air balloon being inflated during the Philippine International Hot Air Balloon Fiesta at Clark Freeport Zone in Pampanga province, north of Manila February 12, 2015. According to the organizer, a total of 32 hot air balloons are part of the four-day event. (Photo by Erik De Castro/Reuters)

Classic antique cars are seen at an auto dealer in West Branch, Iowa, March 6, 2015. Iowa, the American heartland. Endless farm fields and quiet towns. 56,273 square miles that are soon to become the focus of the nation as the long process of electing the next U.S. president begins. (Photo by Jim Young/Reuters)

A policeman controls traffic at 42nd Street and 7th Avenue as New York City remains without electricity caused by a blackout that affected the entire city and most of the eastern part of the nation August 15, 2003 in New York, New York. More than 50 million people were affected by the outage, in Toronto, Detroit, Cleveland and New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images)

In this August 31, 2017, photo, mock fish are displayed to offer to the ancestors during the “Hungry Ghost Festival” in Hong Kong. Countless hungry and restless ghosts are roaming Hong Kong, and the world, to visit their living ancestors, at least according to Chinese convention. In traditional Chinese belief, the seventh month of the lunar year is reserved for the Hungry Ghost festival, or Yu Lan, a raucous celebration marked by feasts and music. (Photo by Kin Cheung/AP Photo)

The British Ecological Society has announced the winners of its annual photography competition, Capturing Ecology. Taken by international ecologists and students, the winning images will be exhibited at the society’s joint annual meeting in Ghent in December. Here: Overall runner-up; Toucan, Mark Tatchell. (Photo by Mark Tatchell/British Ecological Society)