Five units of Dublin Fire Brigade are tackling a large blaze at a former school.
Fire crews from Kilbarrack, North Strand and the city centre are at the scene at Belcamp College in Dublin 17.
It's understood the second floor of the building is the centre of the fire and firefighters are now trying to bring it under control.
A water tanker and a turntable ladder are being used to to help quench the fire.
Firefighters are using the turntable ladder as a water tower to pump water onto the upper floors of the building.
The building is derelict and no injuries have been reported.
Dublin Fire Brigade tweeted: "Five units are now on scene at the fire in Belcamp College, the upper floors are well alight. Smoke is visible in the area."
There have been a number of arson attacks on the building recent years.
The second and third floors of the main building at Belcamp College were set alight during one incident in July 2016.
Five units of the fire brigade were needed to fight the fires on that occasion.
