Most of those killed are policemen and forensic team officials who were examining the explosives stored at the police station, the report said.
The death toll could climb further, with five of the injured still in critical condition, NDTV said.
Reuters could not immediately verify the reason for the blast. Jammu and Kashmir police did not immediately respond to Reuters requests for comment.
Earlier, a local police official told Reuters that an explosion had ripped through Nowgam police station. The official said fire had engulfed the compound and fire tenders had been rushed to the spot, with casualties feared.
The blast comes four days after a deadly car explosion in Delhi, which killed at least eight people in what India has called a terror incident.