Liam Paterson and Will Springer

Several hundred G8 protesters made a concerted effort earlier today to storm the perimeter fence surrounding the G8 summit at Gleneagles. Riot police and mounted officers charged the crowd as attempts were made to set fire to a police watchtower. Reinforcements of riot police were rapidly flown to the site by Chinook helicopter.

As the police formed a cordon round the damaged area of fence, a sit-down protest started and a stand-off ensued. Police soon fanned out from the broken fence and cleared the field of protestors.

The group who attacked the fence had broken off from the official march and represent the first sign of trouble at the site of the G8 summit itself.

The official anti-G8 march on Gleneagles took place after it was previously cancelled on the grounds of "public safety" following outbreaks of violence in Stirling and Auchterarder.

Numerous complaints were made about the earlier decision with many feeling that the cancellation would be seen as provocative. However, following negotiations between anti-G8 groups and police, the go-ahead was given, although only protesters already within a sealed-off area around Auchterarder were allowed to take part.

The 4,000 marchers, holding banners, chanting and accompanied by a piper, made their way to the Gleneagles perimeter fence where they began their protest. The march was led by lawyer Aamer Anwar, SSP leader Colin Fox and Respect MP George Galloway.

Mr Galloway commented: "When, exactly, did this become a police state? When did the police get the power to call off demonstrations here in this free country of ours?...If they [the police] wanted to do the human race a favour, they should march into Gleneagles and arrest the whole gang of them."

Peter Wilson, the chief constable of Fife Constabulary, described the decision to allow the march to proceed as "very difficult". He felt, however, that there had been a "reasonable guarantee" of a peaceful protest, although he made it clear that his sympathies with the protesters demands to march had to be weighed against the rights of the local citizens.

In Edinburgh, approximately 300 protesters who had been turned back from Auchterarder gathered on Princes Street and blocked traffic. Later a smaller group broke away from police and ran up Cockburn Street chased by officers. Control was soon regained and the crowd were moved up South Bridge toward the University area.

Protestors pull at the fence. Picture: Getty Images

Earlier trouble in the G8 zone included:

• About 200 people dressed in hooded tops with scarves obscuring their faces barricaded roads and hurled missiles at police in Stirling. Cars and shop windows were damaged. A spokesman for Central Scotland Police described the actions as "isolated incidents". There were two arrests.
• Several police officers have required hospital treatment following the Stirling confrontations. Seven police have since been released. Their injuries are believed to be minor.
• Near Stirling, about 30 demonstraters took part in a blockade on the M9, forcing shut the main north-south motorway. Police have warned motorists to avoid the area leading to Gleneagles Hotel, the summit venue. Heavy disruption is predicted around the A91 in Bannockburn, near Stirling, with traffic being diverted.
• Around 50 so-called eco-warriors blockaded a bridge between the town of Crieff, where American delegates are understood to be staying at a top hotel, and Auchterarder. The group used tree trunks and branches to block either end of the bridge and held up a sign stating: "G8 Democracy has to wait". The town of Auchterarder has since been sealed off by Police.
• In Edinburgh, at least 200 police encircled most of the main Exchange financial district, which includes the headquarters of the Clydesdale Bank, Standard Life Group and Scottish Widows, from about 6am. Uniformed officers with small riot shields close at hand had closed off all the entry points to the area although workers were allowed to go through on foot.