Archaeologists at the Museum of London Archaeology (MOLA) have unearthed prehistoric tools at the new site of United States embassy In London.

A flint tool dating to the Palaeolithic Period (approximately 700,000 to10,000 BC) was discovered during an excavation at the site located in Vauxhall, in South London.

The tools could be one of the earliest prehistoric objects found in London and hint at the first settlers of the city.

"What we have found may be the earliest archaeological evidence currently known from London. It will be interesting to see how this evidence relates to other prehistoric structures on the nearby Thames foreshore," senior archaeologist Kasia Olchowska said in a statement.

London's long and rich history is often thought to have begun with the arrival of the Romans.

According to archaeologists, a river consisting of smaller channels with sandy and gravelly islands in between used to once flow at what is now South London.

Prehistoric people settled on the fertile and marshy banks of the river that provided them access to rich food sources. The site also served as a perfect hunting ground for prehistoric communities.

Archaeologists hope that the rare discovery of flint tools would provide evidence of prehistoric activity in the region.

"The flint tools found at the United States Embassy site are a rare discovery. In a City that has seen so much development, these fleeting glimpses of prehistoric people rarely survive," Olchowska said.

"We hope to be able to reconstruct and have a better understanding of the prehistoric landscape of a much wider area than at present," she added.

MOLA will carry out further analysis of the flint tools to establish firm dates and learn more about their production and use.

The other discoveries made at the site include a 12m-long prehistoric fish trap, tools dating to Mesolithic (10,000 to 4,000 BC) and Bronze Age (2,000 to 600 BC) and evidence for camp fires.