The dead included policemen, government officials and forensic staff who were examining the explosives at the time, Nalin Prabhat, director general of police for the federally administered region of Jammu and Kashmir, told a news conference on Saturday.
He said the cause of the blast late on Friday and the extent of the damage were being investigated.
Indicating there was no militant involvement in the incident, Prabhat said forensic and chemical examinations of previously recovered explosive materials were under way when "an accidental explosion" occurred on Friday night.
"Any other speculation into the cause of this incident is unnecessary," he said.
The identification of the bodies was under way, as some have been completely burnt, a police source said.
"The intensity of the blast was such that some body parts were recovered from nearby houses, around 100 to 200 metres away from the police station," the source said.
Earlier, a local police official told Reuters an explosion had ripped through Nowgam police station.Â
The official said fire had engulfed the compound and fire tenders had been rushed to the scene.
The blast occurred four days after a deadly car explosion in the Indian capital New Delhi killed at least eight people in what the government has called a terror incident.
Nuclear-armed neighbours India and Pakistan have for decades fought periodic wars over the disputed region of Kashmir, which they both claim in full and rule only in part.
