BEIJING -- The number of railway passenger trips fell sharply in the first 15 days of China's 40-day Spring Festival travel season amid stringent epidemic control measures, data from the national railway operator showed Friday.

From Jan 28 to Feb 11, passengers made 52.33 million railway trips, down 68.8 percent year on year, according to the China State Railway Group Co Ltd.

In light of a sporadic resurgence of COVID-19 cases and measures to reduce people's movements, the group previously lowered its estimate of railway passenger trips from 407 million to 296 million for the travel peak.

To reduce the flow of personnel and curb the spread of the epidemic, many places across China have encouraged residents and migrant workers to stay put for the festival.

China's Spring Festival travel season is commonly regarded as the world's largest annual human migration. People across the country usually enjoy a week-long holiday for family gatherings and celebrations of the lunar New Year, which falls on Friday this year.