The violence in Bihar during Ram Navami was well-planned and the mastermind was the Bajrang Dal convener of the Nalanda district, the police said.
Kundan Kumar and the other accused planned and executed the communal clashes through social media and a WhatsApp group which had 456 members.
He was the admin of the WhatsApp group which was formed just ahead of the Ram Navami, said Jitendra Singh Gangawar, Additional Director General of Police, Bihar.
He said the Bajrang Dal leader surrendered after the administration began to attach his properties. The other admin of the group, Kishan Kumar, has also surrendered.
"In the WhatsApp group, a conspiracy was plotted to spread violence and fake and misleading posts targetting one community were shared," Mr Gangawar said.
Initial investigations reveal the group was also being used to instigate people to spread fake videos against the members of the other community on social media.
Police said a case was registered against 15 people in connection with Nalanda's communal clashes and five of them have been arrested, while two others - including Kundan Kumar - have surrendered.
"A search is on to catch the missing accused," they said.
Some mobile phones have been recovered from the possession of the arrested men through which they uploaded the alleged contents.
On March 31, violence rocked Biharsharif during a Ram Navami procession, resulting in the death of a young man, while several others were injured. Clashes between two groups were reported in Bihar's Rohtas district as well.
Bihar Chief Minister Nitish Kumar had earlier alleged that communal tensions in the state were triggered by some people indulging in "gadbad" (mischief).
"Communal tensions during Ram Navami festivities at Sasaram and Bihar Sharif are disturbing. Such incidents happened for the first time in the area. It's not natural," Mr Kumar said.
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