ST. PETERSBURG, December 12 (RIA Novosti) - The death toll in a blast at an ore mine in Russia's northern Murmansk Region has risen to 12, a local emergencies official said on Friday.

The blast occurred late on Thursday, as workers were preparing to carry out a controlled explosion at the Rasvumchorrsky mine eight kilometers (4.9 miles) from the town of Kirovsk.

"Rescuers have found the bodies of three workers who were previously listed as missing. The current death toll is 12," the official said, adding that another five workers had been hospitalized with various injuries.

All the bodies have now been brought to surface.

Initial reports said at least nine workers were killed in the blast and the ensuing fire, and that three others were still missing. The fire has now been extinguished.

Russia's industrial safety watchdog, Rostekhnadzor, has sent a team of experts to the site for further investigation.

The regional prosecutor's office in northern Russia has opened a criminal investigation into the accident.

The mine is operated by the Apatit company, a major Russian producer of the phosphate minerals used in making fertilizer. The company operates three more mines in the region with estimated reserves of 3.5 billion tons of phosphate ore.

Apatit announced on Friday it had suspended production at the Rasvumchorrsky mine until further notice.

"Operations at Apatit's other mines are continuing as usual," the company said.