HONG KONG — At least 18 people were killed and dozens of others injured when a double-decker bus crashed on Saturday in a rural area of Hong Kong, the authorities said.

The bus was traveling from a horse-racing track in the district of Sha Tin to Tai Po Center in Hong Kong’s New Territories when it turned over, shearing off part of its roof, according to news media reports. The bus was operated by Kowloon Motor Bus, one of the main bus operators in Hong Kong.

At least 62 others were injured in the crash, including 15 people hospitalized in serious condition and 10 who were critical, the Hong Kong Hospital Authority said.

The cause of the crash was not immediately known, the police said. Passengers said the driver had been behind schedule and driving fast, Now News, a cable news outlet, reported. One man told the outlet as he sat on the roadside with his head wrapped in a bandage that the driver had seemed as if he were flying an airplane “around the bends.”

The crash was the deadliest in Hong Kong since 2003, when 21 people were killed when a double-decker bus broke through a guardrail and careened off a road.

While Hong Kong has a well-developed and generally safe public transportation system, fatal bus crashes have persisted. In September, a bus driven by a man who had worked several consecutive 13-hour days crashed, killing three people.

The latest crash is likely to revive concerns about the long working hours of bus drivers in Hong Kong. Drivers have complained that they receive low base salaries, $1,700 to $2,100 a month, and are compelled to drive long hours to earn more. More than three-quarters of bus drivers work 50 to 60 hours a week, according to a 2016 survey conducted by the Hong Kong Confederation of Trade Unions.

Guidelines put in place in 2010 limit drivers to 14 working hours a day and a maximum of 11 driving hours. Drivers’ unions have called for pay raises and a drop in the maximum driving hours.

Carrie Lam, Hong Kong’s top official, said after the crash Saturday that she was creating an independent panel led by a judge to examine the safety of public transportation, particularly buses.

Ms. Lam said after the crash last year that she didn’t believe new laws governing drivers’ hours were an answer, and that any solution had to address broader questions of worker shortages.

“It is a question of how we can ensure the bus operation is safe in Hong Kong,” she said, “which requires also not only regulation on the part of the government, but also full support and cooperation of the bus companies.”