United Airlines suffered yet another computer-related problem that forced a brief ground stop for all domestic mainline flights Sunday, the airline said in a brief statement.

"We have issued a ground stop for all domestic mainline flights due to an IT issue," UA spokeswoman Maddie King said. "We are working as quickly as possible to resolve this issue and get our customers to their final destinations. We apologize for the inconvenience to our customers."

There has been no acknowledgement of how many flights were cancelled or delayed. The ground stop lasted approximately two hours, and flights resumed around 9:15 p.m. EST.

United flies an average of 4,500 flights per day. Mainline flights are those operated by United itself, not its regional partners or subsidiaries.

This is the second time in three months that United has been forced to ground its fleet after a computer glitch, though, to be fair, other airlines have suffered through technological issues that have resulted in major delays and cancellations – Southwest and Delta in August, and British Airways in September.

NOTE: TravelPulse will update this story as more details become available.