Flights disrupted across US Northeast after air traffic centre outage

Damaged communications lines at a key air traffic control facility in Philadelphia had been repaired, allowing airports across the US Northeast to resume operations after hours of disruptions, the nation's transportation secretary said.

Hundreds of flights were cancelled, including more than 600 into and out of Newark Liberty International Airport, as the outage hit every major airport in the New York City area on Monday.

Transportation Secretary Sean Duffy said in an online post that "it will take some time to clear all existing delays" despite the repairs.