The digital collection Mesopotamia Photographs has been created by Gerard Bugler. He has digitized some 300 photographs taken in Mesopotamia between 1915 and 1919 by captain Charles Henry Weaver who worked with the Red Cross. The digital collection can be viewed in sets ordered by cities and themes. The site contains additional information about cities, some digitized texts and background information about captain Weaver.
This website and other online materials about Mesopotamia during the First World War are presented in a very useful overview at War Letters 1914-1918.