Tens of thousands of Scottish independence supporters marched in Edinburgh on Saturday, as calls grow for a fresh vote on Scotland breaking away from the United Kingdom with Brexit scheduled for within weeks.

The march set off from Holyrood Park and marched up the Royal Mile in the heart of the Scottish capital The march set off from Holyrood Park and marched up the Royal Mile in the heart of the Scottish capital Photo: AFP / Andy Buchanan

The demonstrators, many carrying Scottish flags, some wearings kilts and a few playing musical instruments -- including bagpipes -- set off from Holyrood Park in the heart of the Scottish capital.

Some chanted "What do we want? Independence" as the throng of people made its way up the city's famous Royal Mile.

Many demonstrators carried Scottish flags and some played music along the way Many demonstrators carried Scottish flags and some played music along the way Photo: AFP / Andy Buchanan

"Scotland is second class in this union," said Peter Johnston, 22, one of the organisers of the march.

Pressure is growing in Scotland for a second independence, as the country voted by 62 percent against leaving the European Union Pressure is growing in Scotland for a second independence, as the country voted by 62 percent against leaving the European Union Photo: AFP / Andy Buchanan

"As an independent nation it will be world leading in many ways. In the United Kingdom we don't reach our full potential."

Among those present was lawyer and Scottish Nationalist (SNP) lawmaker Joanna Cherry, who was behind one of the successful legal challenges to Prime Minister Boris Johnson's decision to suspend parliament.

The march was organised by All Under One Banner, a group set up after the 2014 referendum to continue campaigning for independence The march was organised by All Under One Banner, a group set up after the 2014 referendum to continue campaigning for independence Photo: AFP / Andy Buchanan

She was also one of the main backers of a law passed last month forcing Johnson to ask the European Union for more time to avoid crashing out of the EU without a deal.

Pro-independence campaigners say another vote on breaking away from Britain is necessary because Scotland voted heavily against quitting the European Union Pro-independence campaigners say another vote on breaking away from Britain is necessary because Scotland voted heavily against quitting the European Union Photo: AFP / Andy Buchanan

"I'm sick of the Tory rule," said attendee Donna Barkley, 47, a bus driver. "I'm sick of being told what to do... We need independence today."

The group organising Saturday's march, All Under One Banner, claimed more than 200,000 people turned out for the rally -- far exceeding their predictions.

The march included a number of musicians playing traditional Scottish instruments such as fiddles and bagpipes The march included a number of musicians playing traditional Scottish instruments such as fiddles and bagpipes Photo: AFP / Andy Buchanan

Police Scotland did not give an estimate of the crowd's size.

Scotland voted against independence in a 2014 referendum by 55 percent.

But nationalists argue that the 2016 British referendum in favour of Brexit means another independence referendum is necessary -- because Scotland voted by 62 percent to stay in the European Union.

Scotland's First Minister Nicola Sturgeon, leader of the SNP, has argued that Brexit will devastate the economy.

Nationalists also argue that some people voted against independence thinking it would guarantee their place inside the EU.

"Scotland in particular has a lot of people coming from all over (the world) and everybody is pretty much unhappy with this situation," said Serena Micalizzi-Coyle, a 50-year-old tour operator on the march, referring to Britain's impending departure from the EU.

"This is a good day to demonstrate that we are united," she added.

Sturgeon, who wants a second independence referendum in 2021, was unable to attend the march, but tweeted a message of support.

"Be in no doubt - independence is coming," she said in the message.

A small number of pro-Union protesters carrying Union Jack flags staged a counter-demonstration in central Edinburgh.