CAIRO — Egyptian security forces on Saturday overran a Cairo mosque in which hundreds of supporters of ousted president Mohammed Morsi had barricaded themselves for nearly 24 hours after a day of gun battles in the heart of the capital.

It was unclear by nightfall what had become of the protesters, who had been detained after security forces had escorted them from the scene. Egyptian state television declared that “the crisis is over.”

But Sunday brought demonstrations and clashes in several other cities across the country. And the eerie silence from Cairo’s al-Fateh mosque as the evening curfew took effect signaled only that the military-led government remained determined to crush Egypt’s pro-Morsi protest movement.

The Muslim Brotherhood, which backs Morsi, and the Brotherhood-led Anti-Coup Alliance called for more protests — every day for the coming week — in the same central square where hundreds of pro-Morsi protesters were killed on Friday. The group vowed that the protesters would perform their evening prayer there.

But the country’s military-backed government signaled Saturday that it is not backing down, either.

“This state and this people are now under attack,” said Mostafa Hegazy, an adviser to interim President Adly Mansour. Hegazy said the state would defeat the “terrorists” and would soon implement the political road map laid out by Egypt’s military after it wrested control from Morsi last month.

Under the government’s increasingly violent crackdown, the voices of Morsi’s supporters have gradually slipped offline and off their defiant protest stages. Much of the leadership of Morsi’s Muslim Brotherhood, which led two sprawling protest camps until they were cleared in a deadly assault on Wednesday, is now in jail, missing or in hiding. Increasingly, a host of young people, wives and other relatives of the missing Islamist leaders who once ran this country have become the spokespeople for a protest movement that is now swiftly losing power but is no less defiant.

On Saturday, the intense standoff at al-Fateh mosque erupted suddenly into a prolonged gunfight, the chaos and panic spilling into side streets and the wider neighborhood as security forces opened fire and shots returned from the mosque’s minaret and windows. On Friday, the protesters, including medical personnel and wounded, had taken refuge in the mosque from gunfire outside in Ramses Square on a day of widespread violence that left at least 230 people dead nationwide.

The number of dead, which has steadily mounted since security forces raided the pro-Morsi protest camps on Wednesday has deepened fears of a slide toward full-blown civil conflict in this already deeply divided nation.

Egypt’s government said Friday’s death toll included 57 members of the police and said it was considering measures to outlaw the Muslim Brotherhood. The group was banned, and regularly repressed, under the regime of president Hosni Mubarak.

Government spokesman Sherif Shawky blamed the Brotherhood on Saturday for Egypt’s ongoing violence, calling the demonstrations “the furthest thing possible from peaceful.”

“Eighty percent of nationwide deaths were caused by the Brotherhood using weapons to attack citizens and police,” he said. “The police used the highest levels of self-restraint.”

The Brotherhood has accused the security forces of opening fire on unarmed demonstrators.

In the early afternoon on Saturday, before the fighting broke out, soldiers had negotiated a safe exit for some of those trapped inside the mosque. But those trying to flee, mostly small groups of women, and the troops escorting them had to navigate through an angry mob of civilians, many of whom said they wanted to “get to” the “terrorists” inside. Some carried sticks and knives.

“The Muslim Brotherhood is inside, and the people are outside, trying to get in,” said Adel, a paramedic who stood by with an ambulance team and gave only his first name to avoid harassment in the tense area.

The previous day, armed vigilantes known as Popular Committees had joined police and army troops in seeking to quell demonstrations.

Hani Nawara, a former assistant to the minister of health under Morsi, was among those who had taken refuge in the mosque overnight and managed to get out Saturday afternoon. Soldiers escorted Nawara and another doctor out, Nawara said. But the only reason they made it past the mob alive was because “we didn’t have beards.” Others, he said, were arrested promptly by the military.

Then came the sudden and confusing bursts of gunfire.

At the height of the standoff, footage broadcast on state television showed troops in armored vehicles and exchanging fire with gunmen in the minaret of the mosque.

Later, state television said security forces had cleared the mosque and removed the protesters. Footage aired later showed police officers moving into the mosque and around its main hall, aiming their weapons.

The United States and European countries have grown increasingly critical of the Egyptian government’s actions, threatening to cut aid and reevaluate their ties to the Arab world’s largest state. At a joint press conference with the Qatari foreign minister, German foreign minister Guido Westerwelle warned Saturday of a “a great danger that more blood will spill . . . which indicates the danger of civil war.”

But Egypt’s president defended the government’s actions, saying the state was engaged in a war against terrorism.

“We will triumph simply for the reason that Egyptians have never been more united than they are today,” Hegazy said during a defiant press conference.

At one point Saturday while protesters were being escorted from the mosque, the mob outside identified a man they thought was a member of the Muslim Brotherhood inside a nearby apartment building. They tried to storm the building saying they wanted to lynch him, but soldiers held them back. Others in the crowd said a woman named Shaimaa inside the mosque had spoken to the Arabic news service al-Jazeera and had spread “lies.”

“The military is not able to deal with the situation because of the crowd. Every person they try to get out, you’ll find 600 others trying to get to him,” said Mohamed Gadalla, a bystander.

Ali Ibrahim, a furniture maker from the neighborhood and among those trying to enter the mosque, said he had helped capture a man with “a big beard” and had “delivered” him into military custody. As he spoke, a crowd of young men ran along one wall of the mosque, apparently looking for a way around the barricades.

When the gunfire erupted around the mosque after some protesters had exited, civilian bystanders fled into nearby side streets and alleys, tripping over one another and pressing themselves against walls for safety. It was unclear which side had started the gun battle, but tear gas quickly drifted through the streets, and television footage showed police and military opening fire on the mosque.

Tufts of white smoke were visible at the top of the mosque’s minaret, indicating that someone there was also firing a gun. The Brotherhood accused the security forces of reaching the minaret through an outer door and staging the attack themselves.

Some of those fleeing the scene appeared to be trying to escape not just the gunfire, but also the mob. At one point, plainclothes men caught up with a bearded man who was running and already bleeding heavily from the head. They grabbed him and beat him more.

The security forces arrested the 250 remaining protesters inside the mosque, al-Jazeera reported.

The Muslim Brotherhood’s Freedom and Justice Party reported on its website Saturday that the son of Mohammed Badie, the Brotherhood’s supreme guide, had been shot dead in Ramses Square during Friday’s clashes.

The Egypt Independent, an English-language news website, said that Badie’s family home in the southern town of Beni Suef was “searched” Friday night and then set ablaze.

On Saturday, Prime Minister Hazem Beblawi also defended the government’s actions against the protesters.

“Despite everything on Wednesday, I say it represents a good achievement,” Beblawi said in a brief interview aired on state television. “We want reconciliation,” he said. “But there cannot be reconciliation with those whose hands are tainted with blood. There will be no reconciliation with those who have borne arms against their brothers, those who have disregarded the law.”

In the northern city of Alexandria and in Minya, a city 150 miles south of Cairo, thousands of people marched through the streets chanting against the coup. Minya has suffered a number of attacks on churches in recent days.

State media reported attacks on security forces in an industrial suburb north of Cairo and in the city of Suez on Egypt’s vital canal Saturday. In the southern city of Assiut alone, security forces detained 72 Morsi supporters, the state-run al-Ahram newspaper reported. The city has long been a bastion of Islamist support.