A Kurdish fighter from the People's Protection Units (YPG) fires his rifle at Islamic State militants as he runs across a street in Raqqa, Syria, July 2017. (Photo by Goran Tomasevic/Reuters)

A helicopter is silhouetted by glowing embers as it makes a water drop at the “Old Fire”, which burned in Calabasas, California, U.S., June 4, 2016. (Photo by Gene Blevins/Reuters)

A motorcycle sits at the site of a destroyed home after the Soberanes Fire burned through the Palo Colorado area, north of Big Sur, California, July 31, 2016. (Photo by Michael Fiala/Reuters)

A fighter of Libyan forces allied with the U.N.-backed government fires a shell with Soviet made T-55 tank at Islamic State fighters in Sirte, Libya, August 2, 2016. (Photo by Goran Tomasevic/Reuters)

A member of Libyan forces allied with the U.N.-backed government fires a weapon on a pickup truck during a battle with Islamic State militants in Giza Bahreya, in Sirte, Libya October 27, 2016. (Photo by Hani Amara/Reuters)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

Members of the Iraqi Army fire towards Islamic State militant positions at the south of Mosul, Iraq December 10, 2016. (Photo by Alaa Al-Marjani/Reuters)

Rebel fighters from the Ahrar al-Sham Islamic Movement fire a heavy machine gun during what they said was an offensive to take the northwestern city of Idlib March 24, 2015. (Photo by Khalil Ashawi/Reuters)