Amid the flames and plumes of smoke, police horses were forced to tread carefully through the burning debris towards protesters

Police stun grenades hit the ground with an earth-shaking bang, the air was a pungent cocktail of burnt metal and plastic, sweat and manure. Activists wearing balaclavas and masks were on the hunt for a fight.

To the untrained ear, they sounded like bombs exploding.

Melbourne’s CBD resembled a war zone, but it wasn’t explosives or heavy gunfire raining over Spencer Street Bridge.

It was police stun grenades, hitting the ground with an earth-shaking bang.

The CBD resembled a war zone. Picture: Jake Nowakowski

Their potent contents filled the air, forcing hundreds of rabid protesters to run from the convention centre on the river which they had come so close to storming.

Rubber bullets and rounds of tear gas were also fired at anti-war demonstrators who moments earlier had overturned protective metal fencing outside the centre.

Fires burned in the middle of Clarendon St after demonstrators ripped apart public waste bins and launched shopping trolleys at officers stationed on the bridge between the crowd and those inside the convention centre.

Fires burned in the middle of Clarendon St. Picture: Jake Nowakowski

Amid the flames and plumes of smoke, police horses were forced to tread carefully through the burning debris towards protesters.

In several cruel acts, the animals were not spared from the assaults launched on the force.

Their own faeces, along with tomatoes and manure, was hurled at them, before the pack launched it all at officers.

The air became a pungent cocktail of burnt metal and plastic, sweat and manure.

Rubber bullets and rounds of tear gas were fired at anti-war demonstrators. Picture: Jake Nowakowski

Horses were pushed in the face and their reins yanked.

Riot officers drew their batons and firmly held their shields in front of their bodies, uniformed officers stood shoulder-to-shoulder and mounted police advanced on the group, driving them further away from the weapons conference.

One officer was hit in the head by a beer bottle, another by a can of baked beans.

Rocks and rubbish were also hurled through the air.

Officers had items hurled at their heads. Picture: David Crosling

Police later reported that analysis on one projectile revealed acid.

While half of the crowd clashed with police on the Spencer St side of the bridge, their combative associates wreaked havoc outside Crown Casino’s dining precinct.

The crowd’s chants and dress depicted support for an incoherent medley of causes.

Organisers branded themselves as “anti-war”.

But some in the so-called protest for peace donned the Russian flag, while others waved anti-Israel signage and yelled “get out of our rally” to a man who appeared to support the Jewish community.

And many of those who ambushed the city – wearing balaclavas and black masks to hide their faces – were on the hunt for a fight.

Police who had been called off crime-fighting duties to keep the city safe were branded as “terrorists”, with the time-rich protesters urging them to “get a real job”, seemingly unaware of the irony of such a slur.

Some could be heard yelling “get those animals off those horses”.

Amid an ugly stalemate, it was the rain which ultimately saw off many of the protesters.

Despite the anarchy on the streets, inside the Land Forces expo, it was largely “business as usual”, as exhibitors showcased their cutting-edge defence technology from across the globe.

Attendees, who said they respected the right of people to protest, had been encouraged to stay indoors.

It was ‘business as usual’ inside the Land Forces expo as protests raged outside. Picture: David Crosling

Some were heckled as “baby killers” and a few had objects thrown at them on their way in, while members of the PNG Defence Force were allegedly assaulted. But many were oblivious to the scenes outside, having avoided using the main entrance.

Former Defence Minister Christopher Pyne, the chair of munitions company NIOA’s advisory board, said what they were doing inside the conference allowed those protesting to do what they were doing outside.

“We are defending freedom and their right to protest. But they should do so peacefully, not violently,” said.

“They wouldn’t be able to protest this way in Moscow, Beijing, Tehran or Pyongyang, yet perversely they are opposed to the very people who defend their right to gather and express their views.”