Seven of the protesters, including Hindu Sena chief Vishnu Gupta, were detained after they tried to set afire ISIS flags at the protest site, a senior police official said, adding they were held to ensure public safety.
"A video launched by ISIS has declared war on us...We have millions of ISIS sympathisers in our country but we nationalists are not cowards," Gupta said.
The protesters were detained at Parliament Street police station and released later. No case has been registered, the official said.