LONDON (AFP) - A Belgian warship on Friday carried 70 bags of soil from World War I battlefields to London, where it will be laid in a memorial garden ahead of the 100th anniversary of the start of the conflict.

London's famous Tower Bridge lifted to allow the Belgian navy frigate Louisa Marie to sail up the River Thames and deliver the soil to the British warship HMS Belfast.

The bags of soil, which were gathered by more than 1,000 British and Belgian schoolchildren earlier this year, will be placed in a new memorial garden at Wellington barracks in central London on Saturday.

Queen Elizabeth II's husband Prince Philip, 92, was presented with the soil in a ceremony in the Belgian town of Ypres earlier this month, to remember the tens of thousands of Commonwealth soldiers who died in the 1914-18 war.

The soil will be pulled in a horse-drawn carriage past landmarks including Buckingham Palace and St Paul's Cathedral on its way to the garden, which will be officially opened in a year's time.

Lance Sergeant Michael Moran, who helped transfer the soil to the British warship, said the events to mark the centenary of World War I helped to bring "closure".

"I've done two operational tours of Afghanistan but what those soldiers went through in the First World War was far worse. Those were real men," he said.

"When the garden is complete it will be a quiet place to go and pay respects to all those lost in the Great War fighting for our freedom."

Designed by Belgian architect Piet Blanckaert, the Flanders Fields 1914-2014 Memorial Garden is intended as "a symbol of hope and a better future for all", according to organisers.