Irish Rail has said a “big signalling issue” in Dublin caused significant delays across its rail network in the early afternoon.

Power was restored to the Dart service after about an hour, and trains have started running again, although some delays are likely as the day progresses.

In a post on social media, Irish Rail said staff were working to resolve the issues and warned passengers to expect delays of over 80 minutes.

It said knock-on delays on services to and from Connolly Station were also anticipated.

“The safety of our passengers and staff is our primary concern and services will be moved to platforms once deemed safe to do so,” the operator said.

However, the issues were subsequently resolved, and normal service is returning to the network.

The disruption began shortly after 12.30pm and was caused by a power supply issue.

Irish Rail spokesman Barry Kenny told The Irish Times that a signalling fault was identified affecting an area from Lansdowne Road to Donabate.

Once the issue was identified, he said, it was quickly resolved and power restored within an hour.

Trains are running again, but delays are expected through the afternoon as a result of the outage.