PHNOM PENH: Thousands of Cambodians joined a colorful procession on Friday to return what they believe are Buddha's relics to a mountaintop shrine from where they were stolen three years ago.

The relics contained in a golden urn were placed in a float built around a car, resembling a giant golden swan complete with little temples on it. Four Buddhist monks sat on each corner of the float and prayed throughout the journey.

The float was driven some 40 kilometres (25 miles) from the Royal Palace in Phnom Penh to the Oudong shrine. Buddhist monks, government officials, students and laypeople joined the procession on motorcycles and other vehicles.

The urn was stolen in 2013, and recovered a year later but was temporarily placed at the Royal Palace. Four guards at the shrine and one more person were arrested.

The reinstallation took place on a national holiday to celebrate what is locally known as Visak Bochea, said to be the holiest day in the Buddhist calendar marking the birth, enlightenment and death of Buddha. It is known by similar names in other Buddhist countries.

Once the relics arrived at its destination, the procession went around the mountain. The chief monks then walked up to the shrine and received the urn from the culture minister.

Several countries in Asia possess relics believed to have come from the body of Buddha, and the stolen urn holds enormous religious and cultural significance for Cambodia, a predominantly Buddhist nation.

The relics were given to late King Norodom Sihanouk in 1957 by Sri Lanka to commemorate the 2,500th anniversary of Buddha's birth.

Chhreung, Len who traveled some 300 kilometers (200 miles) from northwestern Battambang province to join the parade, said she has no regret spending time, money and energy to be here because the remnants of Buddha's body were sacred for Cambodia and for her.

"Once I learned the news from my relatives in Phnom Penh that the remnants would be reinstalled today, I gave up all my farming work and took a bus straightaway," Chreung Len, 68, said.

She added that she hopes authorities will take more care to safeguard the urn and the relics.