The hearing was presided over by Judge Farshid Dehqani at Tehran’s 1060 branch of special court for government employees.

4 out of the 21 suspects were not present at the hearing and their attorneys defended them.

The second session of the hearing is scheduled to be held on July 19.

In the early hours of January 3, angry demonstrators attacked Saudi Arabia’s embassy in Tehran in protest at Saudi Arabia’s execution of Sheikh Nimr a day earlier.

Police arrested those identified as being involved in the attack and President Hassan Rouhani condemned the move afterwards.

However, the Saudi foreign ministry announced it was cutting diplomatic ties with the Islamic Republic following the angry protests.