About 170 Delta Air Lines domestic flights were canceled Sunday night after a systems outage that also caused several departure delays. The airline said that nearly 80 flights scheduled for Monday were canceled.

"I want to apologize to all of our customers who have been impacted by this frustrating situation," Delta CEO Ed Bastian said in a statement. "This type of disruption is not acceptable to the Delta family who prides itself on reliability and customer service," he said, adding: "I also want to thank our employees who are working tirelessly to accommodate our customers."

The airline, which said that more flights could be canceled over the system outage, announced that a waiver will be given for travel scheduled on Jan. 29 and 30, for rebooking by Feb. 3. Further cancelations are likely to affect Delta hub airports like Atlanta, Memphis and Minneapolis-St. Paul, the airline said.

The outage occurred at 6.30 p.m. EST on Sunday, and services were restored a few hours later. The airline said that all systems were back to normal shortly after midnight Monday. However, departure delays and cancelations could still continue.

Earlier, the Federal Aviation Administration said that all the airline's domestic flights were grounded after a request from the company due to an "automation issue." However, the airline resumed limited operations late Sunday.

The Delta Air Lines statement also said that "unaccompanied minors will not be accepted for flights through noon ET" on Monday.

Flight status for domestic travel can be checked at delta.com and the Fly Delta App.

Several passengers stranded at airports took to social media to express their dismay and anger.

In August, Delta Air Lines suffered a computer breakdown after a power outage in its operations center, leading to the cancelation of more than 2,000 flights over three days.