A man reportedly belonging to a right-wing organisation Monday threw ink at Gujarat MLA Jignesh Mevani and former JNU students union leader Kanhaiya Kumar here, police said.
The two were in Gwalior to address a seminar at the Chamber of Commerce Bhawan here as part of their "Samvidhan Bachao" protest.
Mukesh Pal of the Hindu Sena threw ink at Kumar and Mevani, which left a stain on their shirts, when the two were about to address the seminar, said Additional Superintendent of Police SS Tomar.
Kumar and Mevani later addressed the seminar as scheduled with Tomar informing that its proceedings were videographed.
Tomar said Pal had been arrested for the incident, while another 20 were held for burning effigies of Kumar and Mevani on Sunday.