A computer glitch grounded hundreds of Southwest Airlines flights for several hours on Friday night, an airline spokeswoman said. Most of the flights impacted by the outage were on the West Coast.

"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.

A backup system was activated late Friday night, allowing many flights to resume.

Operations resumed Saturday, according to the airline. The airline says passengers should check flight status because of some residual delays.

In San Jose, the airline started to experience network problems at 7:55 p.m.

Passengers who checked in before this time proceeded to the gate where they are currently waiting. Those who tried to check in after waited at the ticket counter, a San Jose airport spokesperson told NBC Bay Area.

The airline called a ground-stop in effect and no flights were departing or arriving at San Jose International Airport.

Across the country, about 250 flights were affected.

At Los Angeles International Airport, 13 outbound flights were kept on the ground. Another 12 flights that were supposed to land at LAX were also delayed.