In books.google.com, came across "Century of Genocide" by three authors which contains a section on Bangladesh. One of the eye-witness accounts include a narration by Prof. Nurul Ullah of the Dhaka University of Engineering on how the videos in the first post of this thread came about. This section begins on p.311 but that page is not available.
http://books.google.com/books?id=5Ef...1&lr=&pg=PA312