The number 786 is considered holy in Islam.
The incident took place two days after a group of men entered a mosque at Anchra Khurd village in Jind district and allegedly injured three people including an Imam, police said.
Policemen have been deployed in the village to maintain law and order.
After the attack on the Imam on Sunday night, Senior Superintendent of Police Shashank Anand reached the village along with administration officials and spent the whole night there to keep the situation under control.