In the family version (page 6 of the rules), yes. They even eliminate the smoke for you!
If the Target space has a Fire or Smoke marker, remove that Fire/Smoke
marker before placing the POI marker.
However in the experienced game (page 10 of the rules), you adjust their position instead.
In the Experienced game a POI may only be placed in a space without a
Threat marker (Fire or Smoke), Firefighter or another POI. If the POI
Replenishment Target space is invalid, then use this diagram to
redirect the POI. Begin in the Target space and follow the path
created by the arrows as shown until you reach a valid space. The
arrows are also placed on the board for easy reference during the
game. If there are no valid spaces on the path, reroll.