At roughly 7am, after 12 hours of fighting, Brotherhood reinforcements arrived – possibly, bystanders said, because one of the fires had grown too big, and those inside now feared being smoked out. The reinforcements covered their colleagues’ exit with live fire – the Guardian later saw bullets being plucked from the wall. Bystanders said that some Brotherhood members were injured and handed to the authorities during the blaze.

Once the other Brotherhood members fled, protesters stormed the compound and accelerated the blaze. Firefighters said they arrived at 9am – too late to save the building, which is now charred and still filled with smoke. Once the worst of the fire was put out, hundreds re-entered the building, looting and destroying its remaining features.

“It’s a great feeling. I’ve wanted to do this for three years,” said Ahmed Yassin, a student from Alexandria, holding the office nametag of Mohamed el-Badie, the Brotherhood’s leader. “Their offices are being trashed all over Egypt – but this was the most important, because they are running the country from this office.”

Opponents of the Brotherhood detest the organisation because it is perceived to unduly influence Morsi, a political associate, and because it seeks to impose too narrow a vision of Islam on Egyptian society.