UPDATE: Despite Southwest Airlines resuming service late friday, about 64 flights of the company were cancelled as the crew could not make it to the airports on time for departure. The airlines' Spokesperson Michelle Agnew told the Associated Press that 50 flights scheduled for late Friday night departures in the western half of the country and 14 flights scheduled to depart on Saturday morning across the U.S were cancelled. 

Earlier, shortly after mid-night Friday, Southwest Airlines (NYSE:LUV) resumed services after a computer glitch caused a temporary delay in its ground operation throughout the western U.S. the company said in a Twitter update.  

The airlines resumed services using a back-up system and engaging employees through a manual process, leading to a delay in departures, the company said.“Systems are operating and we will begin work to get customers where they need to be. Thanks for your patience tonight,” the airlines tweeted in a message posted on its Twitter page after 11 p.m. Pacific Standard Time, or PST.

"Flights have started to depart, but employees are working through a manual process so their routine work flow is taking a bit longer," Agnew told CNN.

"The manual process is involved because the team doesn't have access to all of the normal tools they would use to be able to communicate and dispatch flights," she added.

Around 14 Southwest flights scheduled to depart from the John Wayne Airport in Orange County, Calif., were cancelled owing to noise curfew in the area, CNN reported.

Southwest Airlines grounded about 250 flights readying for departure after a system glitch prevented staff from facilitating passenger check-ins, issue of boarding pass and other computer-based operations around 8 p.m. PST on Friday, AP reported.

“A system outage has caused us to hold departing flights. Flights in the air are not affected by this. All hands on deck to resolve,” the company tweeted shortly after the problem was detected on Friday night.

Southwest Airlines’ flights on the West Coast were mostly impacted by the computer outage. The Dallas-based airline operates nearly 3,400 flights a day.