Around 100 young people have clashed with riot police in Edinburgh, with fireworks being thrown directly at officers.
Video footage from Niddrie showed officers in riot gear standing in a line while youths lobbed explosives at their feet.
Police Scotland confirmed officers had been subjected to attacks from petrol bombs.
Footage on social media showed bystanders watching as officers were bombarded with explosives and smoke, while teenagers gathered on a green – with some filming it.
Police were called to Hay Avenue at 4.40pm, and buses were cancelled with road closures implemented.
In 2018, Police Scotland set up Operation Moonbeam to tackle Bonfire Night disorder.
Last year, a police vehicle was hit by a Molotov cocktail in Niddrie, and motorbike gangs raced through the area while fireworks were lobbed at the ground.
On Tuesday evening, police were called to Kirkton, Dundee, after youths set off fireworks and lit an illegal bonfire – which was branded “moronic” by the leader of Dundee City Council, John Alexander.
A Police Scotland spokesperson said: “Specialist public order resources, deployed as part of Operation Moonbeam, are currently supporting local officers in the Hay Avenue area of Edinburgh, following reports of a large group of youths involved in the antisocial use of fireworks within the area.
“The police response is ongoing at present to keep the public and emergency service workers safe and local road closures are currently in place.
“Police in attendance are currently being subjected to attacks involving fireworks, petrol bombs and other projectiles – and the public is asked to avoid the area while the response is ongoing.”
Scottish Conservative justice spokesman Russell Findlay said: “Such attacks on police officers are cowardly, reckless and dangerous. Police Scotland need sufficient resources to tackle these thugs.”
City of Edinburgh Council leader Cammy Day said: “I’m appalled to see the scenes in Niddrie this evening. We’ve been clear that this sort of conduct is unacceptable.
“We’ve been working hard throughout the year in our communities to mitigate Bonfire Night-related disruption so it is extremely disappointing to see a minority of people behaving in this way.
“This reckless behaviour endangers lives and, like the majority of people in the community, I share in their dismay and upset at this disgraceful behaviour.
“We are working closely to ensure the community are safe and appeal to anyone who can help identify those responsible to contact police so they can be dealt with appropriately by the justice system.
“Our emergency services have our full support and do a fantastic job of keeping us all safe.”