Egyptian security forces besieged a mosque in Cairo early on Saturday in an effort to force ousted President Mohammed Morsi’s supporters, who are barricaded inside, to leave, leading to a tense standoff, news reports said.

Security forces have been persuading those holed up inside the al-Fath mosque in Cairo's Ramses Square to leave, by promising them a safe exit, but pro-Morsi protesters continue to stay inside, the BBC reported.

Television channels aired footage of police in riot gear near the entrance of the mosque, but there were no signs of violence or forced entry, the report said.

An estimated 1,000 people were believed to have entered the mosque following Friday’s violence, during which more than 80 people died and about 1,000 protesters, belonging to Morsi’s Muslim Brotherhood Islamist political organization, were arrested.

Several among those who sought refuge inside the mosque have left, but scores remain inside, and according to two protesters who spoke to the BBC, they did not trust security forces’ promise of safe passage.

Security officials said armed protesters inside the mosque opened fire on the police, official state news agency MENA reported.

Pro-Morsi protesters have vowed to renew demonstrations on Saturday and throughout the next week after deadly clashes with security forces caused about 700 deaths this week across the country.

“The demonstrations will kick off every day throughout the week from the same points today’s demonstrations were launched in Cairo, Giza and the provinces,” a statement published on Friday on the Muslim Brotherhood’s website said.

In the statement, Morsi’s supporters reiterated their “commitment to fully non-violent demonstrations” and denounced “all attacks on places of worship as well as public and private property.”

On the streets of Cairo, armored security personnel continue to patrol, while the army blocked all entrances to Tahrir Square -- the flashpoint of demonstrations in 2011 that led to the ouster of former President Hosni Mubarak.

Meanwhile, groups that lend support to the army-backed interim government in Egypt have called for counter-demonstrations in the coming days, the BBC reported.