As opponents of President Mohamed Morsi again marched to the presidential palace Tuesday night, his Islamist supporters packed a square about two miles away — near enough, several said, to take action to protect the building and their president if necessary.

“Of course, we will protect the palace,” said Mohamed Abdelsalam, 59, a government worker who was at Rabaa al-Addaweya Square with thousands of other Morsi supporters waving the green flags of the Muslim Brotherhood, Egypt’s dominant political Islamist organization. “We will not allow anyone to go inside there.’’

It did not come to that, but the rally of Muslim Brotherhood supporters was more than a show of support for Morsi and the controversial Islamist-backed draft constitution that Egyptians are to vote on Saturday amid legal chaos. It was also a show of force, a gathering of men and women who said that “the people” — by which they meant themselves — “and the police are one hand.”

In recent days, opposition protesters have described having their wrists bound, being brutally beaten and interrogated by Morsi’s Muslim Brotherhood supporters during 15 hours of violent street clashes outside the presidential palace last week, during which both sides hurled rocks and wielded clubs. Protesters said their Islamist captors called them “infidels” and forced them to “confess” to being paid to stoke violence, an interpretation of events that a spokesman for the Brotherhood’s political party denied.

“The group and the party don’t use violence and have no inclination to the use of violence,” Mourad Aly, a spokesman for the party, told the Associated Press.

But as they rallied to chants of “the Koran is our constitution!” Tuesday night, many Islamists spoke openly about what they considered to be their rightful role in protecting the palace. In a larger sense, they spoke of protecting what they consider to be the legitimate outcome of the revolution that ousted strongman Hosni Mubarak nearly two years ago: a democratically elected, Islamist president and the referendum on a constitution drafted by a democratically elected, Islamist-dominated assembly.

“We caught over 300 people, definitely,” said Samir Hassan, 40, an Arabic teacher in a leather jacket and wire rim glasses, referring to protesters whom he and his colleagues captured, men he described matter-of-factly as “thugs.” “The opposition has said they want to cancel the referendum. But the people will protect the legitimacy,” he said.

Hassan described a system that was supposed to be at work last Wednesday, when the two sides faced off in the streets in front of the palace separated by a line of police officers who did little to keep them apart. He said that after he and his colleagues caught any protesters trying to throw rocks or shooting a pellet gun, they would haul them into their crowd, careful to encircle them to “protect them from anyone attacking.”

“The injuries they sustained were because of their resistance and their attempts to flee,” Hassan said. “We were cautious. All were handed over to the police in good shape so that they could confess. They were handed over to police and our role ended.”

A man standing beside Hassan, who did not want to give his name, clarified their role.

“The Muslim Brotherhood does not replace the state’s responsibility for protecting the palace,” he said. “Our role was only to help police as much as possible.”

The benign account differs from the ones that protesters have given to human rights activists. But it speaks to how Hassan and other political Islamists regard themselves as a peaceful, honorable, God-fearing line of defense. They insist that they are forced into violence only by anti-Morsi demonstrators, people they often cast as dirty and crass and bent on destruction.

“Those people just want chaos,” said Abdelsalam, who works in the Finance Ministry, referring to the opposition forces. “Here we have no thugs, no destruction, no molotovs. We are not trying to break things down,’’ he said, gesturing to where vendors were roasting corn and people were chanting “pray, pray for the prophet.”

In support of their position, he and others note that most of those killed last Wednesday were from their own ranks and that the opposition now includes figures from the old Mubarak regime, which outlawed the Brotherhood and forced the group underground for decades, a fate the Brotherhood is determined to avoid in the future.

“Here are the true Egyptian people — not at the palace,” Abdelsalam said. “We are not leaving. Here we are the true Egyptians.”

Abigail Hauslohner, Ingy Hassieb and Sharaf al-Hourani contributed to this report.