Thousands of Luas commuters are facing disruption as Green Line services are expected not to run the remainder of the day because of a technical fault.
Services are suspended on the St Stephen's Green to Brides Glen route.
Luas operator Transdev said the fault was with the overhead wires.
A Luas spokesperson said "services are expected to be down for the remainder of the day. There will be no services over peak time today".
In a statement, Transdev said that the location of the fault has been identified and a number of trams have been damaged as a result of it.
It said services will resume at 6.30am tomorrow.
Tickets are valid on Dublin Bus, the spokesperson added, but warned that passengers should not walk on the tracks for safety reasons.
A bus service is also operating between the Dundrum and Brides Glen Luas stops.