Given the sophistication of the device used, it is very clear that it is a very well planned attempt to disturb the communal harmony of Hyderabad.
It is an attempt by the outsiders( be it pakistani or al qaeda) to show the Indian muslims that they are not secure in India and hence should be united with them to fight. Irrespective of clan or community or religion all Indians need to stand united to face this menace of our times.