In Omdurman, the largest city in Sudan, the Qadiriyya Sufi order meets every Friday outside Sheikh Hamed Al Nil mosque, which houses the tomb of their 19th century Sufi leader. (Photo by Ala Kheir, John Burns and Ibrahim Algrefwi/Brownbook)

A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/Reuters)

This photo provided by Running Press and Quarto, Inc. shows Feline Fox from the book, “Cats in Hats”, published by Running Press. The book released on March 24, 2015. (Photo by Liz Coleman/Running Press/Quarto, Inc. via AP Photo)

Tsetse, six-year-old daughter of Dukha herder Erdenebat Chuluu, sits among her family's reindeer in a forest near the village of Tsagaannuur, Khovsgol aimag, Mongolia, April 21, 2018. Nyamaa is an ethnic Darkhad, herders of northern Mongolia who have historically inhabited the steppe that borders the Taiga forests. (Photo by Thomas Peter/Reuters)

A photographer with a passion for wild animals was able to get up close and personal with one of nature’s deadliest creatures. Alex Suh has traveled to Mexico’s Banco Chinchorro reef twice in the past three years to get into the waters and capture the crocodiles in their natural habitat after an invitation from Yucatan Dive Trek. (Photo by Alex Suh/Caters News Agency)

Aerial photography platform SkyPixel received 27,000 entries to its 2016 competition. Here are the winning shots plus some of our favourites. Here: Dam near perfect. Second prize in the same category was of the Huia Dam in Auckland, New Zealand. Hong Kong-based SkyPixel was launched in 2014. (Photo by Brendon Dixon/SkyPixel)

Three elephant seals put on a show in Roie Galitz's “Three Tanors”, taken on January 7, 2016 in South Georgia Island. The Comedy Wildlife Photography Awards are in full swing, so check out some of the fierce competitors jostling for the top prize this year. Photographers Paul Joynson-Hicks MBE and Tom Sullam founded the awards to spotlight wildlife conservation efforts and to inject some humour into the world of wildlife photography. (Photo by Roie Galitz/CWPA/Barcroft Images)

A woman wearing a wedding dress takes part in the so-called “brides' match” at the FIFA Fan Fest in Kazan, a host city for the 2018 FIFA World Cup, Russia June 30, 2018. (Photo by Alexey Nasyrov/Reuters)