TENS of thousands of Scottish independence supporters took to the streets of Glasgow yesterday in one of the biggest rallies Scotland has seen since opposition to the Iraq war in 2003.

Police estimated 35,000 people took part in the All Under One Banner event which began in Kelvingrove Park and ended at Glasgow Green - 5,000 more than police said took to the streets to protest against military action in Iraq in 2003, which was considered to be one of the biggest ever displays of public opinion in Britain. Organisers of yesterday's event estimated that as many as 90,000 joined the march.

Some supporters of Scottish independence were confronted by men giving Nazi salutes and waving union flags as they walked along Clyde Street. Police are investigating the incident.

One independence supporter, who asked not to be named, said: “There was about eight of them, shouting abuse and squaring up to the crowd. A couple of them gave Nazi salutes. They were looking for a square go. Police officers held them back.”

SNP MSP Stuart McMillan later tweeted about a separate incident which happened on the corner of Renfield Street and Argyle Street.

He said: “On the Indi march and just had a Nazi salute and the middle finger from your supporters @scotlandinunion.”

Scotland in Union is described on its website as “a non-party not for profit group which unites people around a positive view of Scotland in the UK”.

When asked about the incident he witnessed, McMillan said: “There were a group of pro-union protestors. I saw two police officers and one of them was facing the pro-union protestors when it [the Nazi salute] was made. It was approximately 1.10pm.”

A spokesman for Scotland in Union said of McMillan’s tweet about the organisation: “These disgusting smears are becoming more and more desperate from prominent nationalists who should know better.”

A spokeswoman for Police Scotland said there were no arrests at the march, but added: “We are aware of this picture [of the Nazi salute] online and we’ll look into this matter.”