A U.S. army soldier exercises in front of a M270A1 multiple launch rocket system as they prepare for a live-fire training exercise of the 6-37th Field Artillery Regiment at a training area near the demilitarized zone separating the two Koreas, in Cheorwon, South Korea, March 9, 2016. (Photo by Kim Hong-Ji/Reuters)

A man flies a kite made of 110 Tukkal or paper lanterns for the Hindu festival of “Makar Sankranti”, which marks the start of spring, in Ahmedabad January 13, 2011. (Photo by Amit Dave/Reuters)

In this April 13, 2015 file photo, a Thai woman splashes water on people from the back of a truck during the Songkran water festival to celebrate Thai New Year in Bangkok, Thailand.Thailand's military government is putting a dampener on the annual nationwide water fight. Despite Thailand's worst drought in 20 years, the junta says it has no intention of limiting the virtually around-the-clock water throwing that defines the three-day Songkran festival. Instead, it has decided to impose morality measures. (Photo by Sakchai Lalit/AP Photo)

People wrapped in blankets sit on the road as they are evacuated from a hotel after an earthquake in Kumamoto, southern Japan, in this photo taken by Kyodo April 14, 2016. A powerful earthquake with a magnitude of 6.5 knocked over buildings in southern Japan on Thursday evening, and police said people may be trapped underneath. (Photo by Reuters/Kyodo News)

Greek actress Katerina Lehou, playing the role of High Priestess, lights a torch during the dress rehearsal for the Olympic flame lighting ceremony for the Rio 2016 Olympic Games at the site of ancient Olympia in Greece, April 20, 2016. Fire spurted from the concave mirror as a priestess, kneeling in her long, pleated dress before a ruined Greek temple, focused the blazing sun's rays on her metal torch. Come rain or shine on Thursday's official lighting ceremony, Rio de Janeiro has now secured its Olympic flame, which will burn in the main Olympic stadium throughout the Aug. 5-21 games. (Photo by Yannis Behrakis/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 internally displaced Afghan girl plays near their shelter at a refugee camp in Kabul January 13, 2015. (Photo by Omar Sobhani/Reuters)

Two F-15E Strike Eagles wait to receive fuel from a KC-135R Stratotanker during exercise Red Flag 15-1 on their way to Nellis Air Force Base, Nev., Jauary 23, 2015. The F-15s are assigned to the 4th Fighter Wing. U.S. (Photo by Airman 1st Class Aaron J. Jenne/Reuters)