BEIJING - China's Ministry of Civil Affairs (MCA) said Wednesday that an estimated 520 million people mourned the deceased at graveyards or cemeteries during the three-day Tomb-Sweeping Day holiday, up 15 percent from last year.

The number was based on figures from the ministry's 150 key memorial sites and cemeteries, which received a record-high 7.01 million people on Wednesday, or the Tomb-sweeping Day on the Chinese lunar calendar.

From Monday to Wednesday, those monitored memorial sites received 17.91 million people, up 21.4 percent from 2011, according to a statement from the MCA.

No major accidents or large-scale traffic congestions were reported during the holiday, said the statement.

A separate report from the railway authority said that over 20 million people travelled by train from Sunday to Tuesday, and the number of train passengers is expected to exceed 7.2 million on Wednesday, while the average daily level for last April was about 5.2 million.

Besides commemorating family members, over 10,000 people attended an elaborate ceremony in Huangling county, Shaanxi Province Wednesday to pay homage to Huangdi, or the Yellow Emperor, who was considered to be the initiator of Chinese civilization and the ancestor of the Chinese.

The Yellow Emperor, a sovereign and cultural hero in Chinese mythology, is believed to have reigned from 2,697 BC to 2,598 BC. His deeds have been embellished with time -- he has been credited with introducing the systems of government and law to human kind, civilizing the Earth, teaching people many skills and inventing all manner of items.