Arson crews are investigating if a fire at a southeast Houston hotel was set intentionally.

The fire started on the mattress of a room at the Palace Inn off the Gulf Freeway near Dixie Farm Road just before 11 p.m. Monday.

Officials said the fire spread to the wall and filled the second floor of the hotel with smoke.

Investigators said someone was in the room where the fire started 20-30 minutes before the fire started.

Firefighters said the fire could have been accidental with the occupant leaving a cigarette near the bed before leaving.