Stray dogs stand on tombs in Diamond Hill cemetery in Hong Kong, China, 04 April 2017. According to the lunar calendar, the Qingming Festival is observed on 04 April . The Qingming Festival, also known as Tomb-Sweeping Day, is marked by Chinese people by going to the cemetery to cleaning up tombs, bring flowers, and making offerings to their ancestors. (Photo by Jerome Favre/EPA)

U.S. soldiers from the 3rd Cavalry Regiment take part in an artillery exercise on forward operating base Gamberi in the Laghman province of Afghanistan December 24, 2014. (Photo by Lucas Jackson/Reuters)

An activist kicks the shields of the military police officers during a demonstration in the military zone of the 27th infantry battalion in Iguala, Guerrero, January 12, 2015. Activists and relatives of the 43 missing trainee teachers from Ayotzinapa's teacher training college broke into the military zone, located less than a mile from where the students went missing, in an attempt to look for the missing students.The remains of only one of the 43 students has been identified so far. (Photo by Jorge Dan Lopez/Reuters)

For the Torajan people of Indonesia, death is part of a spiritual journey: families keep the mummified remains of their deceased relatives in their homes for years – and traditionally invite them to join for lunch on a daily basis – before they are eventually buried. Here: Todeng died in 2009. A young relative of his, Sam, lights him a cigarette and changes his glasses. (Photo by Claudio Sieber Photography/The Guardian)

Partially constructed notched burial plots are seen at the construction site of an underground tunnel designated for traditional Jewish burial at the Givat Shaul cemetery, on May 14, 2015, in Jerusalem, Israel. Underground cemetery being built by the Israeli Burial Society in Jerusalem due to a decrease in available land for traditional Jewish burials. (Photo by David Vaaknin/The Washington Post)

An Egyptian actress working at the Pharaonic Village simulates ancient agriculture scenes during a show marking Sham el-Nessim, or “smelling the breeze”, in Giza, Egypt, Monday, April 13, 2015. The holiday signifies the arrival of Spring, a uniquely Egyptian tradition practiced since the days of the Pharaohs. (Photo by Amr Nabil/AP Photo)

A clown plays the violin during the XXI Convention of Clowns, at the Jimenez Rueda Theatre, in Mexico City, Mexico, October 19, 2016. In the wake of the creepy clown sightings in several states of North and South Americas and Europe that caused widespread panic, professional clowns from across Latin America came together at an annual convention in Mexico to give a serious message: “We are clowns, not killers!”. Around 200 clowns took part in the 21st International Clown Convention, dressed in bright coloured clothes and makeup, and chanted the word as they clicked group pictures to counter the “creepy clown” craze. (Photo by Carlos Jasso/Reuters)

Firefighters work to quell a fire on an alleged clandestine gasoline storage in the Ixtlahuaca community, Mexico on January 5, 2016. Looting broke out at dozens of stores in Mexico on Wednesday on the sidelines of protests against a steep gasoline price increase as authorities detained more than 200 people. (Photo by Mario Vazquez de la Torre/AFP Photo)