More than 100,000 supporters of Egypt's Islamist president staged a show of force Friday ahead of massive protests later this month by the opposition, chanting "Islamic revolution!" and warning of a new and bloody bout of turmoil.

Adding to the combustible mix, comments by the U.S. ambassador that were interpreted as critical of the opposition's planned protests sparked outrage, with one activist telling the diplomat to "shut up and mind your own business."

Friday's mass gathering was ostensibly called by Islamists to denounce violence, but it took on the appearance of a war rally instead. Participants, many of them bearded and wearing robes or green bandanas, vowed in chants to protect Morsi against his opponents. Some who addressed the crowd spoke of smashing opposition protesters on June 30, the anniversary of Morsi's assumption of power.

"We want to stress that we will protect the legitimacy with our blood and souls," declared Mohammed el-Beltagi, a senior leader of the Muslim Brotherhood, the Islamic group from which Morsi hails.

Most participants were bused in from elsewhere in the Egyptian capital or from far-flung provinces. They waved Egypt's red, white and black flag as well as the green banner of Morsi's Muslim Brotherhood and posters of the president. Many raised their fists in the air.

Brotherhood members in red helmets and carrying white plastic sticks manned makeshift checkpoints, searching bags and checking IDs as demonstrators streamed into the venue.

Friday's rally was the latest evidence of the schism that has torn Egypt apart in the two years since autocrat Hosni Mubarak was ousted in a popular uprising. That division has descended the country into deadly street battles and taken on a clear religious character after Morsi took office a year ago as the nation's first freely elected leader. In the year since, Egypt has been divided into two camps, with the president and his Islamist backers in one, and secular, liberal Egyptians, moderate Muslims, women and minority Christians in the other.

The past year has also been marred by constant political unrest and a sinking economy. Morsi's opponents charge that he and his Brotherhood have been systematically amassing power, excluding liberals, secular groups and even ultraconservative Salafi Muslims. A persistent security vacuum and political turmoil have scared away foreign investors and tourists. Egypt's already battered economy has continued to slide, draining foreign currency reserves and resulting in worsening fuel shortages and electricity cuts, along with increasing unemployment.

The president's supporters charge that the opposition, having lost elections, is trying to impose its will through street protests.

"They threaten us with June 30. We promise them they will be smashed that day," warned hard-line Islamist Tareq el-Zommor, who spent more than two decades in jail for his part in the 1981 assassination of President Anwar Sadat.

"June 30 is Islamic," he said as the crowd chanted behind him.

"Our battle is an identity battle, against communism and secularism," read one banner carried by protesters. "The people want to implement Islamic Shariah law," declared another.

"I am here to support the legitimacy of an elected president who was chosen by the people through the ballot box," said Saad Ismail, a 43-year-old teacher from the Nile Delta province of Beheira.

Assem Abdel-Maged, a hard-line Islamist leader addressing the crowd, threatened that any attempt to oust Morsi would be met with an Islamic revolution. On Thursday, he told a gathering in the southern city of Minya that those conspiring against Morsi include Coptic Christian extremists, communists and remnants of Mubarak's regime.

"Our dead will be in heaven, and their dead will be in hell," he said.

The main boulevard where the rally was held, along with several side streets were packed as protesters streamed in for hours and the crowd grew to more than 100,000.

Opposition leaders were not impressed by the turnout.

"Those 100,000 are not going to scare the people. We have collected petitions of 15 million people," said Mahmoud Badr, one of the main organizers of the June 30 protests. "They brought people from the provinces that stretch from Cairo to (the southern city of) Aswan. This is their top capacity."

After a months-long petition drive, opposition organizers announced on Thursday that they had collected up to 15 million signatures supporting Morsi's ouster and an early presidential election.

Meanwhile, U.S. Ambassador Anne Patterson, who has repeatedly been accused by the opposition of bias in favor of Morsi, caused outrage this week when she said she was "deeply skeptical" the protests will be fruitful and defended U.S. relations with Morsi and his Brotherhood as necessary because the group is part of the democratically elected Egyptian government.

"Some say that street action will produce better results than elections. To be honest, my government and I are deeply skeptical," she said at a seminar Tuesday organized by a Cairo research center. "Egypt needs stability to get its economic house in order, and more violence on the streets will do little more than add new names to the lists of martyrs."

Her unusually frank comments were widely interpreted as referring to the June 30 demonstrations.

Leading opposition activist Shady el-Ghazali Harb said Patterson showed "blatant bias" in favor of Morsi and the Brotherhood and her remarks had earned the U.S. administration "the enmity of the Egyptian people."

"The Muslim Brotherhood is ready to offer Egypt on a golden platter to the United States in exchange for Washington's support. It is no surprise that she would say that," he said.

Another prominent opposition activist, George Ishaq, counseled Patterson in a television interview to "shut up and mind your own business." Christian business tycoon Naguib Sawiris posted a message on his Twitter account addressed to the ambassador saying, "Bless us with your silence."

The United States has had its own frustrations with the mainly liberal and secular opposition, which has been beset by divisions. During a visit by U.S. Secretary of State John Kerry to Egypt in March, he pressed the main opposition grouping, the National Salvation Front, to reverse its decision to boycott parliamentary elections expected later this year or early in 2014.

Washington, Egypt's longtime economic and military backer, has maintained relatively warm ties with Morsi. The Obama administration has praised him for mediating a truce late last year between Israel and Hamas, the Islamic militant rulers of the Gaza Strip, and for maintaining Egypt's peace treaty with Israel.

"This is the government that you and your fellow citizens elected. Even if you voted for others, I don't think the elected nature of this government is seriously in doubt," Patterson said. "Throughout Egypt's post-revolution series of elections, the United States took the position that we would work with whoever won elections that met international standards, and this is what we have done."

Meanwhile, privately owned TV network ONTV aired footage of what it said was Patterson's convoy of black SUVs in a visit to Khairat el-Shater, a powerful figure in the Muslim Brotherhood who is widely suspected to exercise vast influence over Morsi.

The visit drew criticism from the opposition. The U.S. Embassy declined comment.

"Is this democracy that she visits a man who holds no post in the Egyptian state," Harb said.

Morad Ali, spokesman for the Brotherhood's Freedom and Justice party, confirmed the meeting but said he was not authorized to disclose details.

"It was not a secret meeting. The ambassador meets with all political parties and this is the deputy leader of the Muslim Brotherhood. Why is this considered interference in Egypt's domestic affairs?" he said.


Associated Press reporter Tony G. Gabriel contributed to this report.