Mariachi musicians prepare to perform to celebrate the Day of the Virgin of Guadalupe outside the Basilica of Guadalupe in San Salvador, El Salvador December 11, 2015. (Photo by Jose Cabezas/Reuters)

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)

Veterans of the Bangladesh war of liberation march past during the celebration of the country’s 45th Victory Day at the national parade ground in Dhaka December 16, 2015. (Photo by Ashikur Rahman/Reuters)

Tourists watch the sunrise and pray outside a church on the summit of Mount Moses, near the city of Saint Catherine, in the Sinai Peninsula, south of Egypt, December 9, 2015. (Photo by Amr Abdallah Dalsh/Reuters)

Refugees disembark and make their way to a camp at a hotel touted as the world's most northerly ski resort in Riksgransen, Sweden, December 15, 2015. (Photo by Ints Kalnins/Reuters)

People hold out money as butchers sell their remaining produce of the year at discounted prices during the traditional Christmas Eve auction at Smithfield's market in London December 24, 2015. (Photo by Neil Hall/Reuters)

A salsa dancer performs in the “Salsodromo” parade, which marks the start of the Fair of Cali, Colombia, December 25, 2015. Picture taken December 25, 2015. (Photo by Jaime Saldarriaga/Reuters)

A lady smiles during the annual Calabar cultural festival in Calabar, Nigeria, December 28, 2015. Picture taken December 28, 2015. (Photo by Reuters/Stringer)