BEIJING, Jan. 31 (Xinhua) -- Nearly 7.66 million railway passenger trips were made in China Monday, the fourth day of the Lunar New Year holiday, a 9.1 percent increase on last year, official data showed Tuesday.

The passenger trips could hit 8.3 million on Tuesday as people embarked on return journey with the holiday ending on Thursday, according to China Railway Corporation (CRC).

Nearly 6 million train tickets were sold online Monday, accounting for 69.3 percent of the daily total.

The CRC announced it would lay on 407 additional trains on Tuesday.

During the New Year holiday, hundreds of millions of people go back to their hometowns to meet relatives and old friends, putting huge stress on the transport system.

Chinese people have never been more affluent and keen to travel. Every year, pressure on the transport system is huge, despite improvements in infrastructure over the last few years.

Some 258 million visitor trips have been made in China during the first four days of the Lunar New Year holiday, data from the China National Tourism Administration (CNTA) showed.

From Friday to Monday, China's tourism revenue reached 316 billion yuan (about 46 billion U.S. dollars), up 16 percent year on year, according to the CNTA.