A woman plays with a kitten inside of a line house in downtown Shanghai April 12, 2015. (Photo by Carlos Barria/Reuters)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

A couple watches the sunset over a sea of fog covering the Geneva Lake from Chardonne, Switzerland, 28 December 2015. (Photo by Jean-Christophe Bott/EPA)

In this photograph taken on February 18, 2016, Pakistani children ride on swings in the predominantly Pashtun Korangi District of Karachi. In a rundown district of Karachi, Rabia balks at a neighbour's proposal to vaccinate her children, demonstrating one of the biggest hurdles to eradicating polio in Pakistan by the end of the year: confused and frightened parents. (Photo by Asif Hassan/AFP Photo)

A general view of the ghost town of a former Soviet military radar station near Skrunda, Latvia, April 9, 2016. (Photo by Ints Kalnins/Reuters)

Syrian rescue workers and residents help an injured woman following a reported air strike by government forces on the rebel-held neighbourhood of Haydariya in the northern city of Aleppo on April 10, 2016. (Photo by Thaer Mohammed/AFP Photo)

Kashmiri children play with snow on a wooden foot bridge in the interiors of Dal Lake in Srinagar on January 16, 2017. A cold wave has further tightened its grip in Jammu and Kashmir, with most places in the state recording sub-zero temperatures. (Photo by Tauseef Mustafa/AFP Photo)

A Kenyan Red Cross personnel and a volunteer console a relative of a victim, at the site of a building collapse in Nairobi, Kenya, Saturday, April 30, 2016. A six-story residential building in a low income area of the Kenyan capital collapsed Friday night under heavy rain and flooding, killing at least seven people and injuring over 100 others, Kenyan officials said. (Photo by Sayyid Abdul Azim/AP Photo)