By Kylie Gumpert and Alexander Besant
NEW YORK (Reuters) - Crowds of spectators watched the marching bands, floats and giant balloons of Macy's annual Thanksgiving Day Parade on Thursday, held without incident under tight security almost two weeks after deadly attacks in Paris.
New York officials expected more than 3 million spectators to have lined the route for the city's signature parade in its 89th year. They had urged residents and visitors to carry on with holiday plans, saying there were no credible threats to the United States' most populous city.
President Barack Obama sought to reassure Americans on Wednesday they were safe to travel over the holiday..
Police, who were patrolling in record numbers, arrested a 41-year-old Russian tourist for flying a drone in Central Park near the parade route with his son, 14. No other incidents were reported, a spokeswoman said.
Police walked alongside many parade groups and helicopters hovered overhead amid enhanced security following the Nov. 13 attacks in Paris. Islamic State militants have claimed responsibility for the assault in which 130 people died.
Debbie Irey, 50, a tourist from Salem, Oregon, said security was on her mind as she and her husband watched the parade.
"You can't live in fear," said Irey, who works in the financial sector. "The police officers with guns in Times Square heightens your awareness."
About 50 million people worldwide were expected to have watched the televised 2.5-mile (4-km) parade on a route ending at Macy's flagship store. The show ushers in the U.S. holiday season and the busiest time of year to travel.
Crowds up to 80 people deep in places applauded baton twirlers, stilt walkers and giant helium balloons of such cartoon characters as Snoopy and Hello Kitty, which hovered over the parade route.
Children on their parents' shoulders narrated the parade to those in the crowd unable to see. Some youngsters climbed onto police vans, adding to the holiday atmosphere.
Police had added members of a new counterterrorism unit to parade security. Officers guarded subway entrances and circulated through crowds under mostly sunny skies.
"The security is so stringent in NYC that it puts you at ease right from your arrival at the airport," said Anne Marie Sheehy, 49, of Liverpool, England, who was watching the parade with her travel companion, Paula Deegan, 50.
A Reuters-Ipsos poll shows Americans have become more concerned about threats since the Paris attacks and identified terrorism as the most important problem facing the country.
(Additional reporting and writing by Victoria Cavaliere; Editing by G Crosse, Alan Crosby and Jonathan Oatis)