Vishwa Hindu Parishad (VHP) leader Arun Mahaur was shot dead on Thursday by unidentified assailants on a motorcycle in Agra's Mantola area, police said.
Senior police officials said a hunt was on for the killers.
Members of Hindutva groups roamed the streets following the killing and shops in the Nai ki Mandi area downed their shutters.
There was tension in the area.
Mahaur was vice president of the city unit of VHP.