An opposition fighter from the Failaq al-Rahman brigade fires a heavy machine gun in Jobar, a rebel-held district on the eastern outskirts of the Syrian capital Damascus, on March 19, 2017. (Photo by Amer Almohibany/AFP Photo)

A Pakistani labourer carries bricks on his back at a construction site at a residential area in Islamabad on March 29, 2017. (Photo by Aamir Qureshi/AFP Photo)

Vendors selling vegetables wait for customers under a flyover in the early morning in Ahmedabad, India on February 1, 2017. (Photo by Amit Dave/Reuters)

In this Thursday, February 9, 2017 photo, a Bangladeshi boy pulls a rickshaw loaded with strips of leather at the highly polluted Hazaribagh tannery area in Dhaka, Bangladesh. Hazardous, heavily polluting tanneries with workers as young as 14 supplied leather to companies that make shoes and handbags for Western brands, a nonprofit group that investigates supply chains says. (Photo by A.M. Ahad/AP Photo)

A worker carries a basket of fish, at a wholesale fish market, on the outskirts of Kolkata, March 15, 2017. (Photo by Rupak De Chowdhuri/Reuters)

In this photo taken Sunday, March 12, 2017, a girl Abuk walks home with her brothers and friends after collecting clean water from a water point four kilometers away from her home, in Aweil, in South Sudan. As World Water Day approaches on March 22, more than 5 million people in South Sudan, do not have access to safe, clean water, compounding the problems of famine and civil war, according to the UNICEF. (Photo by Mackenzie Knowles-Coursin/UNICEF via AP Photo)

A light railway train passes through a residential building on March 18, 2017 in Chongqing, China. Chongqing Rail Transit No.2 and a 19-storey residential building have been built across each other. The railway set its Liziba Station on the sixth to eighth floor in the building with noise reduction equipment. (Photo by VCG/VCG via Getty Images)

A picture taken on March 9, 2017, shows a boy playing with a cat next to a 1948 Buick parked outside the home of Mohammad Mohiedine Anis in the formerly rebel-held al-Shaar neighbourhood. (Photo by Joseph Eid/AFP Photo)