NASHUA - A pair of small unrelated fires within a handful of hours of each other kept city firefighters busy Monday night. No one was injured in either fire, officials said.

The first fire happened at about 5:15 p.m. at 38 Royal Crest Drive in the Royal Crest Apartments.

"Fire was reported to be visible in a ground floor apartment," the department said in a press release, adding that the apartment was part of a three-story garden style apartment building.

Firefighters were able to force their way in and put out the fire with a portable extinguisher. A search showed no one was in the apartment at the time.

According to fire officials, two occupants were displaced for the night, but all other occupants were able to return to their residences. An unattended candle that ignited nearby combustible materials was said to be the source of the fire, which was ruled accidental, officials said.

The second fire of the night happened at 10:23 p.m. at 21 Spit Brook Road in the Hampshire Heights apartments. The fire was kept to a 5-foot by 6-foot porch, thanks to an occupant who discovered the fire on returning home from the evening and used a portable extinguisher on the blaze, officials said.

No occupants were displaced due to this fire, which officials said was caused by "improper disposal of smoking materials.

"Many discarded cigarettes were found in a buildup of loose fuels (leaves) on and around the deck and landscape that had ignited," officials said. "Make sure to safely dispose of smoking materials and keep the exterior of buildings clean/clear of potential fuel sources such as leaves or trash."

Fire officials took the opportunity to point out that in both fires, occupants pulled the alarm and evacuated the buildings.

"Residents of multiple family occupancies should never be dismissive of building fire alarm system activation," officials said. "Treat every fire alarm activation as a potential fire and promptly evacuate the building upon the fire alarm sounding."