The United Airlines timetable is pictured in Newark International Airport, New Jersey, July 8, 2015. United Airlines resumed flights at all U.S. airports on Wednesday after they were grounded due to computer issues, according to the Federal Aviation Administration. The FAA issued the order to prevent all United Airlines flights from taking off following a systemwide computer glitch, which was resolved, the agency said. Reuters/Eduardo Munoz

United Airlines flights across the U.S. were cleared Wednesday for takeoff after being grounded due to apparent computer glitches since early morning. The FAA updated the ground stop order just before 10 a.m. EDT.

“We experienced a network connectivity issue this morning,” United said in a statement around 9 a.m. “We are working to resolve this and apologize to our customers for any inconvenience.”

Soon after United issued its statement, a number of flights began taking off, according to tweets sent by passengers.

United apparently made the decision to ground the planes, informing the FAA around 7 a.m.

In 2012 United switched over to the computer system used by merger partner Continental Airlines, the Los Angeles Times reported.

United passengers should expect delays for the rest of the day, the airline said.

People wait in line at the United Airlines counter in Newark International Airport, New Jersey, July 8, 2015. Reuters/Eduardo Munoz

Multiple passengers took to Twitter to provide updates on the situation throughout the morning, saying United agents were hand-writing boarding passes and baggage tickets.