A family had a lucky escape after their home was apparently targeted in an arson attack that gardai believe may have been started with fireworks.
One person had to flee the flames through a window after the flat was torched in Hardwicke Street in the north inner city at 5.30pm on Monday.
Initial indications are that a firework was aimed into the flat and ignited and the resulting sparks set fire to the ground floor property.
Locals said the fire took hold quickly and one resident made their way to safety through a window.
"Luckily they were all up. If it happened while people were asleep it could have been a different story," said one neighbour.
"There was flames and smoke pouring out the windows. The whole flat went up.
"It was the quickest fire I ever saw."
The alarm was raised when a passer-by flagged down gardai.
Emergency crews from Dublin Fire Brigade fought the blaze and brought it under control, but extensive damage had already been done.
The brigade posted pictures showing how the street had to be sealed off as they tackled the fire.
Another photo showed smoke billowing from a window, while a third showed the blaze being tackled through a broken window.
The flat has been boarded up by the council and gardai have preserved the scene pending forensic examination.
The charred and sodden contents of the flat, including scorched doors, could be seen on the ground outside.
A spent firework, called a "seven shot blaster", could also be seen on the ground, but it was unclear if it was connected with the blaze.
The spent firework was later removed from the scene for examination.
Under normal use, the firework shoots seven blasts into the air in sequence before each one ignites into a shower of coloured sparks.
Gardai told the Herald that the matter is under investigation as a case of criminal damage.
A car believed to have been used in the incident was seized by gardai a short distance away from the scene and will also undergo a forensic examination.
One neighbour, who said she has only been living at her flat for a week, said the smoke from the fire had been so strong that she had to leave her home.
While the blaze did not spread to any adjoining properties, the block of flats suffered significant smoke damage.