JAKARTA (THE JAKARTA POST/ASIA NEWS NETWORK) - Grand Imam Nasaruddin Umar of Istiqlal Mosque, South-east Asia's largest mosque, has called on Muslims not to be excessive in venting their frustrations toward those perceived to have insulted the Quran.

Imam Nasaruddin delivered his Friday prayer sermon before tens of thousands of protesters who planned a rally demanding the prosecution of Jakarta Governor Basuki "Ahok" Tjahaja Purnama for alleged blasphemy.

The mosque, flocked by at least 10,000 people, was the starting point for the protesters before the main rally in front of the Presidential Palace.

Imam Nasaruddin has attempted to calm the emotions of the rally participants who had largely incited hatred into the crowds and hoisted banners demanding the killing of Ahok before the start of the prayer.

"It is understandable for Muslims to feel offended if someone insults the Quran. But in expressing the anger, the Quran has clearly stated that it should not be done by crossing the line or in excessive ways," said Imam Nasaruddin, the founder of an Indonesian inter-faith organisation and former religious affairs deputy minister.

He also stated that a legitimate government should be nurtured at all costs as it is the prerequisite for the propagation of Islam and its teachings.

Mr Basuki, a close friend of President Joko "Jokowi" Widodo, previously apologised for causing an uproar among Muslim groups and communities after he was accused of insulting verses in the Quran on September 27 during his visit to the Thousand Islands regency.