A tourist stands on the shore of a private beach in Naama Bay, Sharm el-Sheikh, south Sinai, Egypt, Sunday, November 8, 2015. Britain's foreign secretary says airport security in many cities will need to be overhauled if it is confirmed the Russian plane crash in the Sinai was caused by a bomb planted by the Islamic State group or someone inspired by the militants. (Photo by Vinciane Jacquet/AP Photo)

A boy dressed as the Star Wars character Darth Vader attends a Star Wars themed church service, at the Zion Church in Berlin, Sunday, December 20, 2015. About 500 people, some carrying light saber props or wearing Darth Vader masks, attended the service, more than twice as many as usual on a Sunday. (Photo by Markus Schreiber/AP Photo)

Afghan militia men stand near to the dead body of a beheaded Islamic State group loyalist in the Achin district of Nangarhar province east of Kabul, Afghanistan, Sunday, December 27, 2015. An Afghan official says fighters for the Islamic State group and a militia controlled by a prominent lawmaker have beheaded a total of eight men in tit-for-tat revenge killings in the eastern border province of Nangarhar. (Photo by Mohammad Anwar Danishyar/AP Photo)

Humboldt Penguins swim in their pool as a keeper looks on through a spherical window during the annual stocktake press preview at London Zoo in Regents Park in London Monday, January 4, 2016. A requirement of ZSL London Zoo's license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where it's used to manage the worldwide breeding programmes for endangered animals. (Photo by Alastair Grant/AP Photo)

Christian families living in a refugee camp stand under a tree in Kaga-Bandoro, Central African Republic, Tuesday February 16, 2016. Refugees in the north of Central African Republic say they hope the new president will bring peace but no one is heading home just yet. Thousands are still living in displacement camps in Kaga-Bandoro, a stronghold of the former Muslim rebel group known as Seleka that was in power for nearly a year. The one-time rebels say they are waiting to see how the election turns out before taking any action. (Photo by Jerome Delay/AP Photo)

A woman reacts while walking among the ruins of damaged buildings following heavy fighting between government troops and Kurdish fighters, on March 2, 2016 in the southeastern Turkey Kurdish town of Cizre, near the border with Syria and Iraq. Thousands in Turkey's Kurdish-majority town of Cizre started returning to their homes today after authorities partially lifted a curfew in place since December for a controversial military operation to root out separatist rebels. (Photo by Yasin Akgül/AFP Photo)

Arab Israeli contestant Tallinn Abu Hana poses for the judges during auditions for the first Miss Trans Israel beauty pageant in Tel Aviv, Israel, Thursday, March 3, 2016. The winner will represent Israel at a Miss Trans Star International pageant to be held in Spain in August. Tel Aviv has emerged as one of the world's most gay-friendly travel destinations, standing in sharp contrast to most of the rest of the Middle East, where gays can face persecution. (Photo by Ariel Schalit/AP Photo)

Andrew Hepher, Vice President of Lubricants Technology, Shell unveils the Shell Concept Car in Beijing, China, Friday, April 22, 2016. Built as proof of energy efficiency that can be achieved with the latest technologies, Shell unveiled the concept car ahead of the bi-annual Beijing Auto Show where the world's top car manufacturers will showcase their own upcoming products. (Photo by Ng Han Guan/AP Photo)