A girl sits outside a house during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)





A man sleeps on a wheelbarrow outside a closed shop at a market during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)





Children ride on the back of a truck during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)





People tour a graveyard for Houthi fighters killed in recent fighting, during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)





A poster of a Houthi fighter is seen on his grave, on the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)





People shop at a market during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)





Children ride on the back of a truck loaded with water jerrycans at a camp for internally displaced people in the Dhanah area of the central province of Marib, Yemen, April 30, 2016. (Photo by Ali Owidha/Reuters)





A man and his sons stand at a flooded camp for internally displaced people in the Dhanah area of the central province of Marib, Yemen, April 30, 2016. (Photo by Ali Owidha/Reuters)





Children play in floodwater near a camp for internally displaced people in the Dhanah area of the central province of Marib, Yemen, April 30, 2016. (Photo by Ali Owidha/Reuters)





A girl plays in floodwater at a camp for internally displaced people in the Dhanah area of the central province of Marib, Yemen, April 30, 2016. (Photo by Ali Owidha/Reuters)





A boy cycles at a camp for internally displaced people in the Dhanah area of the central province of Marib, Yemen, April 30, 2016. (Photo by Ali Owidha/Reuters)





People stand at a flooded camp for internally displaced people in the Dhanah area of the central province of Marib, Yemen, April 30, 2016. (Photo by Ali Owidha/Reuters)