Vandals may have been responsible for a Dart train derailment, Irish Rail has said.
Two sets of wheels on one carriage came off the track after the last service out of Greystones, Co Wicklow on Tuesday night struck a boulder.
Gardai have been called in to investigate how the rockfall was caused.
A large hole can be seen next to the coastal path which runs along the cliff face above the busy Dart line sparking concerns that the boulder was dumped on the track deliberately.
“It’s believed it may have been caused by vandals. It is a large boulder. There’s evidence from above on the walkway between Bray and Greystones that a boulder has been dislodged,” a spokeswoman for Irish Rail said.
The accident happened on the Bray side of a tunnel about one mile from the town’s busy station when two sets of wheels, known as bogies, on a four-carriage train, came off the track.
There were 33 passengers and the driver on board, but no-one was injured.
The railway line was closed until mid-morning with busy commuter services and also trains to Rosslare disrupted as checks took place on the track and hillsides around the tunnel.
The boulder which caused the derailment was 2ft across.
The train suffered only minor damage while the impact and damage on the rail lines were not significant, Irish Rail said.