The Rabaa al-Adawiya protest in Cairo was pretty festive this week, despite a government threat on Monday to clear it and the smaller one at Nahda square near Cairo University. Nobody there believed that the security forces – who were authorized by the interim government which was authorized by the army – were really going to do anything, not least since a mandated 24 hours had passed without incident.

This morning all that changed. Military and security coordinated to block off all roads around the Rabaa encampment, and rather than using water cannon and other standard methods of breaking up a sit-in, they followed massive use of tear gas with live fire – the tally at the Rabaa morgue has been reported by journalists inside at at over 100 so far (I’m going with the figures from fantastic reporter @SameralAtrush of AFP who had been inside the encampment for a few days).

From early on hundreds of sympathizers of the ousted president Mursi began to gather in front of tanks and a cordon of military blocking the road at the Midan al-Sa’a (Clock Square) side of Rabaa. Over the course of the morning hundreds more joined them until it swelled to up to a few thousands. Soldiers fired volleys of pretty foul teargas and live fire into the air. But they were hardly careful: at least two people were taken away, apparently dead, by the ambulances that were constantly blazing in to remove the wounded, either by asphyxiation or teargas canisters striking them or the live fire (it wasn’t always clear).

Most of the crowd seemed to have come from other areas and were sometime visitors to the Rabaa encampment, whose numbers varied constantly over the last six weeks, from hardly a few thousand in the mornings, to many thousands at night. But many were also from the local neighbourhood – some of us ran into buildings to escape the teargas and one teenager got a scarf from his flat upstairs for me to wear against the gas.

Crazed angry individuals would suddenly come charging down the street towards the military screaming “Allahu akbar’; one did so shunting himself forward at top speed on a wheelchair. One young guy, probably in his 20s, shouted: “I’m not Brotherhood, but you’re not going to make us slaves again!”

I was really struck generally by how many of the protesters were teenagers or in their 20s and I got the feeling that for many this was another round in the long battle against a fascist military-security system that treats them like cockroaches. They came up with a great new slogan, a variation on the “army and police are one hand” – al-gaysh wash-shurta eed wiskha, “the army and the police are one filthy hand together”.

“They want to rule us by force, we are people who they don’t want to have a voice or rights. They occupied the country by force and want to rule by force. We have prepared ourselves for a million martyrs. We will go back to Rabaa and all the squares of Egypt,” said Saber Mohammed Hassan, a 43-year-old carpenter, in a typical comment. “I was in there at the sit-in, but unfortunately I came out to clean up a bit. My daughter is in there though, she was staying overnight… When we heard the shooting start at 6am, we all came running.”

“In my view, they are doing this (dispersal) for the sake of the police, so that they can reestablish themselves as a force to be reckoned with after what happened on Jan 25, 2011. It’s the police who are leading this operation,” said Mohammed Hassan, a shop manager in his 20s.

Looking around, I wondered what the potential for setting up a new protest site here was – but with the Rabaa al-Adawiya transport stop on the square, it doesn’t seem practical. There are reports of an encampment being set up in Maadi though. Nasr City, Maadi – these are middle class areas of  Cairo where it is not possible at all to generalize that most people are opposed to the Islamists.

The state media machine has tried to depict Rabaa as the work of lower orders from the countryside, sullying the urban landscape of Cairo sophiscates. But it seems to be more complicated than that, just as the income and class melange in the capital is generally hard to pick apart. Indeed, I returned from Nasr City to the ‘affluent’ Mohandiseen district and found security forces having the same pitched battles with youths around the Mustafa Mahmoud mosque area.

It is interesting to note, however, that the Rabaa protest is smack in the middle of a district full of military installations, of both a serious and a frivolous nature – banquet halls, military-owned hotels like the Sonesta, commemorative monuments, administrative headquarters. Some of them border the protest encampment itself. The imposing high walls around these installations are covered with anti-military graffiti – which just shows the meaningless of graffiti, two years after the January uprising, in judging sentiments or trends in the chaos of Egypt today.

I looked for people at Midan al-Sa’a who were not with the Islamists. Most were likely in their homes and set on staying there; shops were all shut. I found one guy who said he was not one of them, but he hardly seemed raptured by the military and coup leader, defence minister Abdulfattah al-Sisi, both of whom state TV are trying to big up into national cults. I suspect this doesn’t really reflect feeling on the street at all.

“They have to break the protests because this is all wrong,” said Mohammed Ahmed, 24, a sales manager from Zeitoun in Cairo. “Egyptians are killing Egyptians. In whose interests? No one knows, everyone is lost. No one knows  if the army is right, or the people, or the Brotherhood, if the army are traitors, or the Brotherhood.”

I saw someone else who didn’t fit the bill of an Islamist supporter, and indeed it transpired she wasn’t, but she was screeching at the top of her voice against the violence. She gave her name as Mona al-Shaer and had the airs of a well-to-do ‘secularist’ who despises the Brotherhood. “We went down onto the streets to protest on June 30, but for them to take billions from Saudi Arabia and the UAE? Or so that Israel can live in peace?” she screamed, standing beside a makeshift hospital cordoned off the street for the injured. “You kill people for a reason, there has to be a reason why they are doing this.”