Military policemen try to open a path ahead for the funeral of 21-year-old Mohamed Adel, one of the army officers who died in yesterday's Sinai attacks, in Al-Kaliobeya, near Cairo, Egypt, July 2, 2015. Egypt launched air strikes on Islamist militant targets in the Sinai peninsula on Thursday, killing 23 fighters a day after the deadliest clashes in the region in years, security sources said. The sources said those killed had taken part in Wednesday's fighting in which 100 militants and 17 soldiers, including four officers, were killed, according to the army spokesman. (Photo by Mohamed Abd El Ghany/Reuters)

Participants re-enact the “Battle of Five Armies” from J.R.R. Tolkien's novel “The Hobbit” in a forest near the town of Doksy, Czech Republic June 6, 2015. According to event organizers, hundreds of enthusiasts dressed as characters such as elves, dwarves, goblins and orcs from the book “The Hobbit” re-enacted the clash. (Photo by David W. Cerny/Reuters)

Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

Damaged train coaches at the site of a train accident, 180 kilometers from Bhopal near Harda district of Mahdya Pradesh, India, 05 August 2015. At least 25 people died when two passenger trains derailed in central India after heavy monsoon rains flooded railway tracks, officials said. Ten coaches from the trains toppled while approaching a small bridge just before midnight. (Photo by Sanjeev Gupta/EPA)

In this photo taken Thursday, August 13, 2015, a man walks past the charred remains of new cars at a parking lot near the site of an explosion at a warehouse in northeastern China's Tianjin municipality. Rescuers have pulled a survivor from an industrial zone about 32 hours after it was devastated by huge blasts in China's Tianjin port. Meanwhile, authorities are moving gingerly forward in dealing with a fire still smoldering amid potentially dangerous chemicals. (Photo by Ng Han Guan/AP Photo)

Chinese paramilitary guards monitoring passengers as they head to their train to travel to their hometowns for the “Spring Festival” or Lunar New Year at Nantong Railway Station in Jiangsu province, near Shanghai Travellers taking part in the world' s largest annual human migration must be home by January 27 to usher in the new year on January 28. (Photo by AFP Photo/Stringer)

Rougine, a 19-year-old female Arab fighter among the Syrian Democratic Forces, made up of US-backed Kurdish and Arab fighters, stands in fatigues embracing another colleague near the village of al-Torshan, 20 km on the outskirts of Raqa on February 6, 2017. (Photo by Delil Souleiman/AFP Photo)

The Doppler on Wheels (DOW) vehicle scans a supercell thunderstorm during a tornado research mission, May 8, 2017 in Elbert County near Agate, Colorado. Doppler on Wheels (DOW) is a mobile doppler radar mounted on a truck that brings instruments directly into storms, allowing scientists to scan storms and tornadoes and make 3-D maps of wind and debris. (Photo by Drew Angerer/Getty Images)