HALIFAX -- Two of the three people found dead in a house fire near Halifax were homicide victims and a man has been arrested, the RCMP said Thursday.

The victims were an 81-year-old man and a 54-year-old woman and the cause of death of another person discovered later inside the home remains under investigation, the Mounties said in a statement.

Police arrested a 30-year-old man Thursday at around 12:45 a.m. after someone rammed two police vehicles with a car in the Milford area, about a half-hour drive from the scene of the blaze that broke out about eight hours earlier. That man remains in custody but no charges have been laid.

"The individual that was involved in the collision with the police cars in the Milford area last evening is a suspect in the house fire," said Cpl. Greg Church.

Church said he could not release any details on the suspect or the victims as the investigation is in its early stages.

He said the bodies will undergo autopsies to determine the causes of death.

Crews responded Wednesday at around 4:30 p.m. as flames engulfed the home on Old Guysborough Road in a rural, wooded area about 25 kilometres northeast of Halifax's airport.

Deputy fire Chief Roy Hollett said crews had to wait Thursday before entering the building to find a third person who was unaccounted for because the first and second floors of the home collapsed.

A spokesman for the Halifax Regional Municipality said one problem in fighting the fire was a metal roof that kept the interior of the house extremely hot.