At least 26 people were injured when militants attacked Pampore tehsildar's office in south Kashmir when candidates of various political parties were filing nomination papers for the civic poll.
Police said militants tossed two powerful hand grenades inside the office complex.
The injured were taken to a local hospital. Three official vehicles were also damaged.
Police have rushed to spot.
Civil polls are to be held in the state after a gap of 27 years from February 1.