A fire at an air traffic control center in Newfoundland forced air traffic controllers in New York and Portugal to handle dozens of additional airliners over the Atlantic on Thursday morning. Many planes had to be detoured hundreds of miles, to their destinations in the United States, the Caribbean or South America, according to air traffic officials.

An electrical fire around 10:30 a.m. Eastern time on Thursday forced the evacuation of controllers in Gander, Newfoundland. About two dozen planes were diverted south, to an area controlled by the New York Air Route Traffic Control Center, in Ronkonkoma, on Long Island. Planes already in the affected area were allowed to continue, because they were on preassigned routes that are protected from other traffic.

For the period of the disruption, which was about two hours, most of the traffic is westbound. Although a few planes were held on the ground in the United States, “from our perspective, it didn’t result in a lot of delays or disruption,” said Laura J. Brown, a spokeswoman for the Federal Aviation Administration.

At the Ronkonkoma center, Patrick McDonough, the representative of the National Air Traffic Controllers Association, the union, said controllers were able to pick up the extra workload partly because many planes were grounded because of the snow storm in the Northeast. He said the New York controllers coordinated with two other air traffic control centers that handle Atlantic traffic, Santa Maria in Portugal, and Shanwick, a merged operation of functions formerly carried out in Shannon, Ireland, and Prestwick, Scotland.