A fiery crash on Highway 63 in northeast Alberta killed the occupants of a small car Monday, but the explosion and fire prevented police from knowing how many people have died.

A small vehicle driving on Highway 663 near Boyle, Alta., entered the larger highway, driving into the side of a tractor trailer carrying about 57,000 litres of gasoline.

The force of the impact resulted in both vehicles catching fire.

"The collision ...was at 4 o’clock in the morning," said RCMP Cpl. John Spaans.

"By the time the fire was small enough so that crews could get to it, it was nine o’clock. So, it burnt, essentially controlled for about five hours before we were able to extinguish the fire."

The driver of the semi-tractor trailer was able to escape with minor injuries, but there were no survivors in the second vehicle. 

The fire was so intense, police can't say what make of car was involved or how many people were inside.

The highway was reopened to traffic later in the day.