US carrier Delta is experiencing world-wide delays after an earlier power outage at one if its hubs.

A computer issue in Atlanta resulted in systems and operations being affected. However a grounding order for all its flights was lifted ealier.

Two flights from Dublin Airport - to Atlanta and New York - were affected.

But these have since departed, with flights DL177 and DL045 both seeing a delay of just over four hours each.

The carrier says it has operated more than 1,260 flights of the nearly 6,000 flights scheduled for Monday.

As of noon ET @Delta has cancelled approx. 365 flights and operated more than 1,260 flights of the nearly 6,000 flights scheduled today.

— Delta News Hub (@DeltaNewsHub) August 8, 2016

"Customers heading to the airport should expect delays and cancellations," the carrier says.

"While inquiries are high and wait times are long, our customer service agents are doing everything they can to assist."

"There may also be some lag time in the display of accurate flight status at delta.com, the Fly Delta App and from Delta representatives on the phone and in airport," it adds.

The carrier has given affected passengers until August 12th to rebook their tickets.

"If your flight is canceled or significantly delayed, you are entitled to a refund. Even if your flight is not canceled, you may make a one-time change to your ticket without fee if you are scheduled to travel," a statement on its website says.