United Airlines grounds all flights around the world

United Airlines said on Wednesday it was forced to ground all its flights around the world due to computer problems.

About 3,500 flights around the world were affected, the US-based carrier said.

"We experienced a network connectivity issue this morning. We are working to resolve this and apologise to our customers for any inconvenience," the airline said in a message posted on its website.

The Federal Aviation Administration, meanwhile, said United's flights were grounded at 8 a.m., Efe nbews agency reported.

"We are recovering from a network connectivity issue this morning and restoring regular flight operations. We have a waiver available at united.com for customers who are able to change their flight plans," said an United Spokesperson.