Grounded United passengers air their complaints online – then start drinking

Airline says service has resumed after technical issues forced grounding of all planes in the US, but delays are expected throughout the day

Thousands of United Airlines flights across the US were grounded for two hours on Wednesday, after what the airline said was a "network connectivity issue".

The airline has said it is working to restore flight operations but residual delays were expected throughout the day for all 4,395 daily departures.