A tribesman loyal to the Houthi movement carries his rifle as he leaves a gathering held to show support for the group, in Yemen's capital Sanaa December 15, 2015. (Photo by Khaled Abdullah/Reuters)

Boys pan for gold on a riverside at Iga Barriere, 25 km (15 miles) from Bunia, in the resource-rich Ituri region of eastern Congo February 16, 2009. Ituri is one of many areas of the country to have experienced bitter ethnic conflict between rival tribes in recent years. Massacres have left tens of thousands dead. It is this fighting that led U.S. authorities to take the unprecedented step of naming Congo in section 1502 of the Dodd-Frank financial regulation act, which says U.S.-listed companies that source gold, tungsten, tantalum and tin from Congo or its neighbours must assure the U.S. stock exchange regulator that their business is not helping fund conflict. (Photo by Finbarr O'Reilly/Reuters)

The remarkable scene was captured by amateur wildlife photographer Ian Salisbury, 62, at the South Luangwa National park in Zambia. The crocodile grabs hold of the elephant's trunk, but it soon becomes clear that he has bitten off a lot more than he can chew by grabbing the huge beast. Mr Salisbury said the elephant “fled rapidly into the bush” after the attack. (Photo by Ian Salisbury/Caters News)

A man dressed as a “Trapajon”, representing entities of nature, poses for a picture after taking part in the Vijanera Festival in Silio, northern Spain, Sunday, Jan. 6, 2013. The Vijanera masquerade, of pre-Roman origin, is the first carnival of the year in Europe symbolizing the triumph of good over evil and involving the participation of crowds of residents wearing different masks, animal skins and brightly colored clothing with its own complex function and symbolism and becoming the living example of the survival of archaic cults to nature. (Photo by Daniel Ochoa de Olza/AP Photo)

The civilised world lies on its knees, a sickness wracking its body. The affliction causes a necrotising of tissues so perfectly uniform in distribution that victims take on the appearance of corpses long before death occurs due to organ failure or secondary infections. ...

Xochimilco – Island of the Dolls – Dead Line. Photo by Ramalama_22

An elephant is used to demolish a house during an eviction drive inside Amchang Wildlife Sanctuary on the outskirts of Gauhati, Assam, India, Monday, November 27, 2017. Indian police on Monday took the unusual step of using elephants in an attempt to evict hundreds of people living illegally in the protected forest area in the country's remote northeast. Police used bulldozers and the elephants in a show of force, and the forest dwellers responded by hurling rocks. (Photo by Anupam Nath/AP Photo)

A saltwater crocodile with a tyre around its neck is seen in Palu river in Palu on January 16, 2018. Indonesian conservation officials are racing against time to locate and rescue a saltwater crocodile that has had a tire wrapped around its for more than a year on the island of Sulawesi. (Photo by AFP Photo/ARFA)