The blast at the historic Mecca Masjid in Hyderabad on May 18, 2007 during Friday prayers had also left 58 others injured.
After initial investigation by the local police, the case was transferred to CBI, which filed a chargesheet.Subsequently, the National Investigation Agency (NIA) took over the case from the CBI in 2011.
Ten persons allegedly belonging to right wing organisations were named as accused in the case.
However, only five of them — Devendra Gupta, Lokesh Sharma, Swami Aseemanand alias Naba Kumar Sarkar, Bharat Mohanlal Rateshwar alias Bharat Bhai and Rajendra Chowdhary — who were arrested had faced trial in the case.
Two other accused — Sandeep V Dange and Ramchandra Kalsangra — are absconding while another accused Sunil Joshi had died.
Investigations were continuing against two other accused.
A total of 226 witnesses were examined during the trial and as many as 411 documents exhibited.
Swami Aseemanand and Bharat Mohanlal Rateshwar are out on bail while three others have been lodged in the Central prison in Hyderabad under judicial remand.
In March 2017, a court in Rajasthan had sentenced Devendra Gupta and others to life in jail in the Ajmer Dargah blast case.