PHNOM PENH, Nov. 25 (Xinhua) -- A ceremony to commemorate those who died in a major stampede three days ago kicked off 7:00 o' clock Thursday morning, with Cambodian Prime Minister Hun Sen and his wife Bun Rany Hun Sen attending the event near Diamond Island.

The whole cabinet, National Assembly members and senators showed up and offered incenses and flowers as sacrifices to the dead. Hun Sen and his wife shed tears during the mourning rite.

Kep Chuk Tema, Governor of Phnom Penh municipality and other city hall officials, delegates for various agencies and sectors also attended the mourning rite, followed by hundreds of local people, who came up voluntarily to show their sorrow for the tragedy, described by Hun Sen as the biggest since the collapse of the Khmer Rouge regime in 1979.

All schools, government agencies and private enterprises across the country fling flags at half-mast and all the places of amusement will keep closed till midnight as Thursday was announced the National Mourning Day.

The Chinese Embassy to Cambodia also half-masts for the lost of lives of the Southeast Asian country.

The Ministry of Foreign Affairs and International Cooperation will hold a Buddhist religious function (Bangskol) in the afternoon to mark the day of national mourning.

Monday, the final day of Cambodia's Water Festival, saw a deadly stampede on a bridge connecting the mainland Phnom Penh and the Diamond Island, which claimed at least 456 lives and wounded more than 700.

When the tightly packed crowd were trying to flee from the narrow bridge on about 9:30 p.m. Monday, many were drowned, suffocated or were trampled to death.

The three-day Water Festival, the largest annual festival of the country, this year attracted over three million Cambodians, many from rural areas, converging to the capital city to enjoy the regatta.