Newly-wed couples attend their group wedding ceremony which was held as part of the Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province January 6, 2016. As many as 15 couples attend this mass wedding ceremony. (Photo by Aly Song/Reuters)

A student activist is detained during a silent protest after Thailand's election commission filed charges against a group for posting “foul and strong” comments online criticising a military-backed draft constitution, in Bangkok, Thailand April 27, 2016. (Photo by Jorge Silva/Reuters)

Armed female members of the militant Palestinian group Islamic Jihad carry Kalashnikov assault rifles as they take part in a rally to protest against US President Donald Trump's decision to recognise Jerusalem as the capital of Israel, in Gaza City on December 11, 2017. (Photo by Mohammed Abed/AFP Photo)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

A group of hikers atop Mount St. Helens on July 21, 2016. Mount St. Helens or Louwala-Clough is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 96 miles south of Seattle, Washington, and 50 miles northeast of Portland, Oregon. (Photo by Raxit Kagalwala)

An Iraqi military vehicle passes displaced Iraqi boys returning to their homes in West Mosul's Oreibi neighbourhood after government forces retook control of the area from the Islamic State (IS) group during the ongoing offensive against the jihadists on May 21, 2017. (Photo by Ahmad Al-Rubaye/AFP Photo)

A grey whale greets tourists in boat in, Baja California, Mexico, March 2017. A pair of newly born grey whale calves intrigued by visiting tourists eagerly swim over to the group to get a closer look. Urged on by their mother, the small calves confidently went up to the tour group who were visiting San Ignacio Lagoon in Baja California, Mexico. This adorable moment was captured by zoologist and wildlife photographer, Mark Carwardine on his visit to the area in March 2017. (Photo by Mark Carwardine/Barcroft Images)

Baker Magadma, a member of Palestinian sports group Bar Palestine, performs on the street in Gaza City, on June 3, 2016. Street workout, which is still new in Gaza, is a growing sport across the world with annual competitions and events. (Photo by Mohammed Abed/AFP Photo)