DALLAS — Southwest Airlines resumed takeoffs Saturday after computer glitch grounded an estimated 250 flights.

Spokesman Brad Hawkins said that although service had resumed, it was far slower than usual because of lingering computer problems. He added that some cancellations are expected but wasn’t sure how many.

Hawkins said earlier that the airline grounded all departing flights late Friday due to a systemwide computer problem. The computer problem affected the airline’s ability to do such things as conduct check-in, print boarding passes and check the weight of the aircraft. He said some flights were on the taxiway and diverted back to the terminal after the glitch occurred. No flights in the air were affected.

Because of the late hour of the disruption, the computer problem affected far more flights on the West Coast, but Hawkins said at least a few on the East Coast also were grounded.

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A spokesman for Los Angeles International Airport said of about 25 inbound and outbound flights remaining Friday, only five departing flights were experiencing delays, of 30 to 80 minutes.

Four Southwest flights were temporarily held in Seattle, said Christina Faine, a Seattle-Tacoma International Airport spokeswoman.

One flight to Oakland, Calif., had been due to leave at 9:20 p.m. and departed before 11 p.m. Faine said late Friday that an airport duty manager, Anthony Barnes, told her the others were expected to depart soon.

Steve Johnson, a spokesman for Portland, Ore., International Airport, said he was not aware of any planes held up there.

The Dallas-based airline conducts an average of 3,400 flights each day.