An Afghan man is carried out of a hospital after receiving treatment following a suicide truck bomb attack in Kabul, Afghanistan August 7, 2015. The bombings were the first in Kabul since Mullah Akhtar Mansour took charge of the Taliban last week, and followed a rare truck bomb attack in an eastern province on Thursday. (Photo by Omar Sobhani/Reuters)

A Syrian boy is comforted as he cries next to the body of a relative who died in a reported airstrike on April 27, 2016 in the rebel-held neighbourhood of al-Soukour in the northern city of Aleppo. The Syrian army was preparing an offensive to retake the whole of Aleppo, as fighting in the divided second city killed 38 civilians in a new blow for a tattered truce. Nearly 200 people have been killed in Aleppo in the past week as rebels have pounded government-held neighbourhoods with rocket and artillery fire and the regime has hit rebel areas with air raids. (Photo by Karam Al-Masri/AFP Photo)

An armed man herds his cattle close to the village of Nimini in northern South Sudan, February 8, 2017. In the chaos of South Sudan's civil war, it took three years for Nyagonga Machul to find her lost children. Machul had traveled from her village to the capital when President Salva Kiir, an ethnic Dinka, fired his deputy Riek Machar, a Nuer, in 2013. (Photo by Siegfried Modola/Reuters)

Iraqi Kurdish female fighter Haseba Nauzad looks through a pair of binoculars during a deployment near the frontline of the fight against Islamic State militants in Nawaran near Mosul, Iraq, April 20, 2016. (Photo by Ahmed Jadallah/Reuters)

Thai emergency staff help the injured after the scene of an explosion near Erawan Shrine, central Bangkok, Thailand, 17 August 2015. An explosion in a busy commercial district in the Thai capital killed at least 15 people. Witnesses said the explosion happened around 7:15 pm (12:15 GMT) at the Rajprasong Intersection, a business area famous among tourists and locals for a revered Hindu shrine. (Photo by EPA/Stringer)

A rose lies on a plastic sheet covering a victim of a Malaysian Airlines Boeing 777 plane which was downed on Thursday near the village of Rozsypne, in the Donetsk region July 18, 2014. International prosecutors investigating the downing of flight MH17 over eastern Ukraine in 2014 say the missile that hit the plane was fired from territory controlled by Russian-backed rebels. They said the missile launcher was brought into Ukraine from Russia. All 298 people on board the Boeing 777 died when it broke apart in midair flying from Amsterdam to Kuala Lumpur. The JIT investigation's findings are meant to prepare the ground for a criminal trial. (Photo by Maxim Zmeyev/Reuters)

Workers lay railway track in a tunnel of the Crossrail project in Stepney, east London, Britain, November 16, 2016. Crossrail, which is Europe's largest construction project, is a railway link which will connect outlying areas to the east and west of London with tunnels under the centre of the capital. (Photo by Stefan Wermuth/Reuters)

A building burns after an explosion on 2nd Avenue on March 26, 2015 in New York City. The seven alarm fire drew firefighters from across the city. A number of injuries have been reported. (Photo by Andrew Burton/Getty Images)