Cleaners paddle though trash left over from a Buddhist festival which sees devotees float candle-lit floral baskets into rivers.

Millions of people around Thailand and neighbouring countries celebrated Loi Krathong by releasing the decorations into lakes, rivers and beaches to honour the "Goddess of Water"

But shocking footage from the Ping River in Chiang Mai, northern Thailand, shows the aftermath, with workers still struggling to collect the mountains of waste three days after the event.

Officials said that 40 tonnes of waste from Loi Krathong baskets would be collected from the river this year, fewer than the 70 tonnes last year.

The Chiang Mai Department of Irrigation said they expected to have them all cleaned up by Friday. Leftovers will be sorted before being made into compost.

Loi Krathong, or Loy Krathong, is said to have started in the 12th century in the ancient Thai kingdom.

Millions of devotees in Thailand and neighbouring countries, including Burma, Laos and Cambodia, now take part in the spectacle.

Meaning ''to float a basket," the event follows the Buddhists belief of paying respect to the religion's water goddess.

The festival takes place on the 12th month of the traditional Thai lunar calendar when there is a full moon. The exact date of Loi Krathong changes every year.

This year, officials have encouraged followers to use bio-degradabe material to avoid harming the environment.

Cleaners paddle though trash left over from a Buddhist festival which sees devotees float candle-lit floral baskets into rivers.

Millions of people around Thailand and neighbouring countries celebrated Loi Krathong by released the decorations into lakes, rivers and beaches to honour the religion's water goddess.

But shocking footage from the Ping River in Chiang Mai, northern Thailand, shows the aftermath, with workers still struggling to collect the mountains of waste three days after the event.

Officials said that 40 tonnes of waste Loi Krathong baskets would be collected from the river this year, fewer than the 70 tonnes last year.

The Chiang Mai Department of Irrigation said they expected to have them all cleaned up by Friday. Left overs will be sorted before being made into compost.

Loi Krathong, or Loy Krathong, is said to have started in the 12th century in the ancient Thai kingdom.

Millions of devotees in Thailand and neighbouring countries, including Burma, Laos and Cambodia, now take part in the spectacle.

Meaning ''to float a basket," the event follows the Buddhists belief of paying respect to the religion's water goddess.

The festival takes place in 12th month of the traditional Thai lunar calendar when there is a full moon. The exact date of Loi Krathong, also spelled Loy Krathong, changes every year.

This year, officials have encouraged followers to use bio-degradabe material to avoid harming the environment.