Ontario Provincial Police have identified two volunteer firefighters who died while battling a massive fire in Listowel on Thursday afternoon.

Police say 30-year-old Raymond Walter and 56-year-old Kenneth Rea died in the blaze at a Dollar Store in the southwestern Ontario town.

The men were members of the North Perth Volunteer Fire Department. Walter was a resident of Listowel, while Rea lived in Atwood, police say.

The fire broke out at about 3:30 p.m., sending flames and a thick plume of black smoke several metres into the air.

Police say firefighters were dousing the flames when they noticed the men were missing. Their bodies were found during a search of the building.

Officials haven't commented on the cause of their deaths.

Firefighters remained at the scene late Thursday to extinguish hotspots.

The OPP and the Office of the Fire Marshal are investigating the cause of the blaze.

Ontario Premier Dalton McGuinty released the following statement Thursday night to offer his condolences:

I was saddened to learn today of the death of two volunteer firefighters in Listowel. On behalf of all Ontarians, I would like to express my condolences to the family and friends and colleagues of these two brave men.

They put their own lives at risk in order to protect their communities, just as firefighters do every day across Ontario.

Our volunteer firefighters take time away from their families to keep us safe. We rely on their selflessness, and today's tragedy is a solemn reminder that we must never take their sacrifices for granted."

Listowel is about 120 kilometres west of Toronto.