Chaos has broken out at live viewing sites across Australia as passionate Socceroos fans set off flares and surged through barriers while watching their side take on the USA.

Fans breached the barriers of Melbourne’s Federation Square on Saturday, after the popular site reached capacity just after 4am.

Despite a rainy and cold morning, punters still smuggled flares, with a glow of red seen lighting the sky during the national anthem.

While fans celebrated the atmosphere, there was disappointment as the Socceroos’ campaign suffered a setback with a 2-0 loss to the American team.

At least two flares were set off among the crowd of thousands.

Former Socceroo Craig Foster, who was the MC at the live site, urged fans to stop letting off the flares.

Victoria Police were out in force managing the rowdy crowd.

One shirtless man was seen being escorted away following a confrontation.

The large crowd donned ponchos, green and gold scarves, with one fan wearing a costume as though he was sitting on Donald Trump’s shoulders.

Eager fans were also were redirected to AAMI Park which also livestreamed the match.

World Cup fever has also spread across several live sites in Sydney, with multiple flares set off at Tumbalong Park in the CBD.

There were more relaxed conditions seen along Brisbane’s South Bank, as thousands of fans watched the blockbuster clash, and excited crowds in Hobart and Canberra.