Egyptian authorities have cleared a Cairo mosque of anti-coup protesters, following a day-long siege punctuated by gunfire, tear gas volleys and mob attacks.

The Fateh mosque in Ramses Square was evacuated on Saturday of protesters holed up since violence flared in the square on Friday evening. Police stormed the building on Saturday evening, moving the protesters out and beyond angry crowds who had formed outside.

Some reports said many of those removed from the building were taken away in police and military vehicles.

Egyptian television channels showed footage of security personnel guarding detained protesters inside the mosque and later leading them away.

Al Jazeera's Mike Hanna, reporting from Cairo, said that it was unclear where those who had been removed from the mosque had been taken by police.

"There have been various reports about what happenend. Witnesses said some had been taken by the army beyond the crowds outside, some were taken into military or police custody."

Authorities later said about 250 protesters were being investigated for "murder, attempted murder and terrorism."

The police action to clear the building came after security forces claimed to have come under attack from gunmen hiding in the building's minarets. Television footage showed security forces firing volley after volley at the building and its minarets.

The protesters inside the mosque denied any link to those firing at the police, saying there was no access to the top of the minarets from inside the building.

One man, Waleed Attar, was among a group who managed to escape the building as gunfire erupted. He told Al Jazeera: "We didn't know where the bullets were coming from."

He said they managed to flee and avoid "thugs" waiting outside. "We found our way between vehicles before the thugs could trap us, we ran for fear of being shot. Many of those trapped were being assaulted by thugs. They said we would all be slaughtered."

Earlier, speaking to Al Jazeera by phone from inside, protester Omaima Halawa said there was shooting inside and outside the building. Cracks of automatic gunfire and screaming could be heard in the background as she spoke. Halawa said there were about 700 people inside, including women and children.

Anti-coup protesters found refuge in the mosque late on Friday after a "day of rage" protests called by opponents of the country's military-led leadership turned to bloodshed.

Reports said at least 95 people were killed in Ramses Square when security forces fired on marchers - the worst violence witnessed on Friday. The Fateh mosque was turned into both a morgue and a field hospital for those injured.

At least 173 people were killed and 1,330 others were injured nationwide on Friday, according to a government spokesman.

Friday's marches were organised in response to police action on Wendesday to remove protesters from sit-ins calling for the return of the deposed president, Mohamed Morsi, and the end of military rule. An estimated 600 people were killed in the operation.

On Saturday evening, fresh protests were held in the Cairo suburbs of Helwan and Giza, and the city of Alexandria, in defiance of a sunset curfew imposed by the interim regime.

PHOTO CAPTION

Supporters of Egypt's ousted President Mohammed Morsi march towards Old Cairo as they carry the coffin, covered with a national flag, of their colleague who was killed during Wednesday' clashes in Cairo, Egypt, Friday, Aug. 16, 2013.

Al-Jazeera