BEIJING -- China added 123 temporary trains to cope with an increase in rail traffic on Monday as the week-long Chinese Spring Festival holiday enters its third day, according to railway authorities.

It is estimated that travellers will make 4.07 million train trips on Monday, up from 2.37 million on Sunday, the day of the Chinese Spring Festival, the Ministry of Railways said in a statement on its website.

On Sunday, 4,193 trains were employed, including 109 temporary trains, with the Beijing and Shanghai railway bureaus registering 222,000 and 504,000 passenger trips, respectively, the ministry said.

Spring Festival, an important occasion for Chinese family reunions, marks the world's largest annual human migration. This year's peak travel season kicked off on January 26 and will last until March 6.