Simon Darvill has undertaken extensive research into industrial locomotives in south Asia, and the results have been compiled into a new website, www.ilsa.org.in which is now live.
There are detailed records of industrial locos which have been used in India, Pakistan, Bangladesh, Afghanistan, Nepal, Sri Lanka, Burma and Bhutan (yes, really!) since the early 1850s.
Included in the section on railways used for military purposes in India up to 1947 are details of railways used for British overseas campaigns up until the end of World War I. This includes the campaign in Mespotamia (now Iraq).
Simon has supplied this site with details of locomotives in Afghanistan; his site also has an Afghan section.
Link doesn’t seem to work