Egypt unrest: The struggle for Tahrir Square
The battle to keep control of Tahrir Square, in the heart of Cairo, has taken on a symbolic importance for protesters calling on President Hosni Mubarak to step down.
Injured and exhausted from clashes with thousands of government supporters, they say they are more determined than ever to hold their ground.
"We have been through hell," says Ahmed Zain. "They started throwing stones, and before dawn they were shooting at us. I swear to God we could not sleep until six in the morning and then we fell down unconscious."
"Mubarak should know we will never leave this place. After he tried to take our blood, we will never leave".
The mood has changed significantly from the carnival atmosphere earlier in the week. There are now mainly men in the square, not families.
In the grassy centre of the square, there are small rallies going on, the protesters chanting anti-Mubarak slogans.
Here, tea is served, people take a quick wash using bottles of water, and volunteers are cleaning up.
But the road leading north, past the pink neo-classical facade of the Egyptian Museum looks like a battleground.
Metal barricades have been erected and are being reinforced with sacks of stones.
The army now occupies a buffer zone close to 6 October bridge, just beyond the museum, and tries to keep back a pro-Mubarak group throwing stones. I see one soldier hit in the eye.
While the military is trying to keep order, the soldiers do not have the correct equipment or sufficient numbers on the ground.
Tanks remain parked at all the entrances to the square.
Anyone who enters needs to be checked by soldiers. They then pass through human chains of demonstrators who apologetically inspect bags and identity cards.
"There are many police officers outside the square who are wearing plain clothes, but they have knives and weapons," says Mohamed. "They are trying to come here. There are others paid by Mubarak's party."
The interior ministry's official denial that it was behind attacks on the protesters and the new prime minister's televised apology are rejected outright here.
People believe the assault was the police state fighting back using familiar dirty tactics.
Many now wear bandages on wounds they have sustained in fighting.
Makeshift clinics continue to operate at the northern edge of the square, near the museum. Volunteer doctors treat cuts, burns and broken bones.
"We have seen people by the hundreds at least. We treat whoever we find because we are all Egyptians," says Dr Murad Mohsen.
Hopes that this could remain a peaceful uprising now look unrealistic, but one woman said she was prepared to pay the cost.
"This is a revolution. I want to play a part in the revolution. We are still so proud of it and I want to be part of it. I know every revolution has a price and we will pay the price."