It's day two of a 48-hour strike by Luas staff in Dublin, affecting thousands of commuters.

The dispute is over a pay claim of up to 54% over the next five years for tram drivers.

Yesterday saw heavier than normal traffic volumes in Dublin city centre, with packed buses and trains, as commuters made alternative arrangements.

A further 48-hour stoppage is planned for next Thursday and Friday.

Owen Reidy of SIPTU said the union could not rule out further action.

"If no progress is made, what I would fear and anticipate is that more action will be announced over the coming weeks," he said.

"We could end up getting into a very protracted, long-running dispute which is something we want to avoid.

"This is the first time in the history of the Luas that we've had any disruption. People have felt that they have very little alternative."

Luas operator Transdev has said the two-day strike - which continues until the early hours of Saturday - will cost the company approximately €200,000.