Italian police fired tear gas and a water cannon at protesters who threw fireworks in a bid to reach a road near a Winter Olympics venue. Violence erupted at the end of a peaceful march by thousands against the environmental impact of the Games and the presence of agents from the United States in Italy.

Police on Saturday battled demonstrators, who appeared to be trying to reach the Santagiulia Olympic ice hockey rink. A group of masked protesters set off smoke bombs and firecrackers on a bridge overlooking a construction site about half a mile from the Olympic Village, which is home to around 1,500 athletes.

Police vans behind a temporary metal fence secured the road to the athletes’ village, but the protest veered away, heading towards the Santagiulia venue. The entire route was lined with police.

Despite the clashes, there have so far been no reports that the protest and resulting road closure interfered with athletes’ transfers to their events on the outskirts of Milan.

The demonstration coincided with US Vice President JD Vance’s visit to Milan as head of the United States' delegation. He attended the opening ceremony on Friday where he was reportedly booed by the crowd.

Mr Vance and his family had been visiting Leonardo da Vinci's "The Last Supper" closer to the city centre at the time of the protest, which also was against the deployment of US Immigration and Customs Enforcement (ICE) agents to provide security to the US delegation.

US Homeland Security Investigations, an ICE unit which focuses on cross-border crimes, frequently sends its officers to overseas events, including the Olympics, to help with security.

The ICE arm at the forefront of the Trump administration's controversial immigration crackdown in the US is known as Enforcement and Removal Operations. There is no indication its officers were sent to Italy.

At the larger, peaceful demonstration, which numbered 10,000, cardboard cut-outs representing trees felled to build the new bobsled run in Cortina were carried by protesters.

Dancers performed to beating drums and music blasted from a truck leading the march, including an expletives-laden anti-ICE anthem.

A banner raised by a group calling itself the Unsustainable Olympic Committee read: "Let’s take back the cities and free the mountains".

Another sign read, "Get out of the Games: Genocide States, Fascist Police and Polluting Sponsors".

Protesters voiced anger at the fossil fuel companies sponsoring the Games. One woman carried an artificial tree on her back decorated with the sign: "Infernal Olympics".

Protester Guido Maffioli said: "They bypassed the laws that usually are needed for major infrastructure projects, citing urgency for the Games."

He claimed the private entity organising the Games would eventually saddle Italian taxpayers with debt.

The demonstration followed another last week when hundreds protested the deployment of ICE agents.

Demonstrators on Saturday said they were opposed to ICE agents’ presence, despite official statements that a small number of agents from an investigative arm would be present in US diplomatic territory and not on the streets.