PHNOM PENH (AFP) - Thousands of Buddhist monks and devotees joined a lavish procession on Friday (May 20) to return a stolen golden urn said to contain relics of the Buddha to a mountain shrine where it was snatched from three years ago.

The urn was placed on a decorated float shaped like a mythological bird and driven from the Royal Palace in Phnom Penh to a shrine at the top of nearby Udong mountain.

The elaborate ceremony was timed to coincide with Visak Bochea, an annual religious holiday marking the anniversary of the Buddha's birth, enlightenment and death.

"Ten of thousands of people greeted the Buddha's relics at the mountain," Mr Seng Somony, a spokesman for the Ministry of Culture and Religion, told AFP.

The disappearance of the golden urn - believed to contain hair, teeth and bones of the Buddha - and several small statues came to light in late 2013, sparking a nationwide manhunt in the Buddhist-majority country.

Authorities recovered the urn and relics during a raid in February 2014 at a house in the southern province of Takeo, around 130km away from the shrine in the former royal city of Udong.

Last year, five men were sentenced to seven years' jail each for stealing the golden vessel.

Mr Seng Somony said the authorities would ensure safety for the urn and relics.

"It will be 24-hour security" at the shrine, he added.

The relics are believed to have been brought from Sri Lanka to Cambodia in the 1950s to celebrate 2,500 years since Buddha's birth.

In 2002, then King Norodom Sihanouk moved the relics from the capital Phnom Penh to Udong, around 45km away, in a ceremony attended by tens of thousands of people.

During the colonial period and later the turmoil of the Khmer Rouge era, Cambodia lost a treasure trove of relics and statues to looters, unscrupulous dealers and greedy governments.

Recently many Western governments, including some renowned museums, have begun returning items to the country.