Traffic at Los Angeles International Airport last year grew 4.7 percent, with 61.8 million passengers passing though the world’s sixth busiest airport, airport officials announced Wednesday.

Los Angeles World Airports, the city agency that runs LAX, reported a 4.6 percent growth in domestic passengers to 45.1 million, with international traffic up 4.9 percent to 16.7 million.

Los Angeles World Airports Executive Director Gina Marie Lindsey said several factors contributed to the growth, including new international service to destinations such as Istanbul, Madrid and Tokyo/Haneda, and additional flights to Beijing, Shanghai and Dubai. She also cited an improving Asian economy and a “modest, but perceptible strengthening” of the Southern California economy.

“While LAX has not come close to seeing its pre-9/11 traffic of 67 million passengers, the 2011 activity demonstrates a stronger travel demand than we’ve seen in several years,” said Lindsey in a statement.

The number of landings and takeoffs of both passenger and cargo aircraft rose 4.8 percent to 603,912.

Total air cargo tonnage was down, falling 3.8 percent to 1.8 million. An 8.6 percent rise in air mail to 80,442 tons was offset by a 4.2 percent drop in cargo freight to 1.7 million tons.

Lindsey called the air cargo decline “somewhat puzzling,” and said her staff would be analyzing the numbers to determine possible underlying causes.