CAIRO — Egyptian police arrested a senior Muslim Brotherhood official and dozens of its supporters yesterday after the Islamist group held a military-style show of force on a university campus.

Mohammed Khayrat Al-Shater, a 55-year-old considered to be the Islamist movement’s third-ranking official, was arrested at his home in Cairo before dawn, security sources said.

Dozens of students and teachers from Al-Azhar University were also detained overnight, the sources added.

“The number of students arrested was not specified, but it could be as high as 180,” a security official said on condition of anonymity. “At least three professors and several student leaders were taken during this sweep,” a Muslim Brotherhood official said.

“The 180 students were detained before dawn during a sweep at the Al-Safa campus, annex of Al-Azhar.” Mahmud Ezzat, a top Muslim Brotherhood official who has been in and out of prison himself in recent months, confirmed the arrests and said that all but 10 of those detained were members of the movement.

The offices of Shater’s import-export company were closed by security and his financial director was also arrested, the Islamist movement said. Student members of the opposition group had organized a demonstration at Al-Azhar University on Sunday during which they held a military-style gathering, with some wearing black hoods and bandanas.

The protest, staged in front of the university dean’s offices, sparked a fierce debate in Egypt on the nature and intentions of the Muslim Brotherhood. State-owned newspapers have attacked the Brotherhood in their columns all week, comparing it to Lebanon’s fundamentalist Shiite Muslim movement Hezbollah.

“The black shirts worn by the students at Al-Azhar University have been associated throughout history with fascism, Nazism and extremism,” the governmental Al-Gomhurriya wrote on Wednesday.

Yesterday, editorialist Mohammed Ibrahim was even harsher.

“We do not want to wake up one morning to find out that the tumor of Muslim Brotherhood militia is spreading in the Egyptian body. I do not want my country to repeat the tragic Lebanese scenario where militia have established a state within the state,” he said. On Wednesday, the Muslim Brotherhood-affiliated student union issued a statement apologizing for “the negative image conveyed by our actions on campus.”

“We acted that way because we felt that nobody was listening or doing anything to defend our freedom,” the statement said. “Our will continues to be ignored and our rights to political participation are being violated on campus,” added the union, condemning the presence of security services in universities and the alleged rigging of student election results.