Mohammed Osama, speaking from the Muslim Brothers headquarters in Cairo, told The Associated Press that 48 members were arrested. The men, detained from at least five Egyptian provinces, included leading figures in the group, a state security prosecution official said on condition of anonymity.

The group planned to demonstrate on Sunday afternoon in front of the downtown parliament building. Generally, demonstrations are tolerated though a violation of Egypt’s decades old emergency laws, but riot police always vastly outnumber protesters. This time, Cairo traffic was knotted for hours and thousands of riot police waited outside the National Assembly, but protesters did not show up.

The Brotherhood instead showed up in front of Al-Fateh Mosque, about 4 kilometers in the sprawling capital, shouting “Islam is coming, coming and the Quran will rule” and “No extremism, no terrorism. We want to rule by the book (Quran) ... Islamic law, Islamic law.”

Some riot police got into place quickly, with The Associated Press seeing a few hundred standing, facing demonstrators, shields in front of them. At the time, the AP saw up to 3,000 demonstrators urging hundreds more people approaching to “come join us, let’s raise our voices together.”

Interior Ministry officials, speaking on condition of anonymity, estimated 2,000 protesters had gathered and said two more demonstrations by the Muslim Brotherhood were simultaneously taking place elsewhere in Cairo. Those officials said there were up to 200 protesters in each of Babelouq Sayda Zeinab districts, and that riot police were present at both.

The Brotherhood estimated 5,000 protesters participated, some raising copies of the Quran and many waving banners against emergency laws and demanding greater freedom to form political parties.

The Muslim Brotherhood was established in 1928 and outlawed in 1954, after the government accused it of advocating the violent overthrow of Egypt’s secular government.

Since the 1970s, the group has pledged to use only peaceful democratic means to establish an Islamic state. It’s believed to have tens of thousands of supporters in Egypt. Its supporters dominate most professional unions and are active on university campuses. It also gained influence in Egyptian politics by forging alliances with legal parties.

Running as independents, the group and its supporters won 17 seats in the 2000 elections, making the Brotherhood the largest opposition bloc in the 454 seat legislature.

Egypt is witnessing unprecedented heated political debate since Mubarak ordered a constitutional amendment earlier this year that would allow more than one candidate to run for president. Egypt currently holds “yes” or “no” referendums for one presidential candidate.