Thousands of Tunisian Islamists and secularists gathered near the parliament building in the capital, Tunis, Saturday in rival protests.
Separated by barriers and police, the two sides shouted slogans and waved flags outside the Bardo Palace where a new constitution is being drawn by lawmakers.
The latest round of protests was sparked when a group of hardline Islamists occupied a university campus near the capital earlier this week to demand segregation of sexes in class and for female students to wear a full-face veil.
The moderate Islamist Ennahda party dominates Tunisia's new 217-member assembly, taking the largest number of seats in the country's first democratic polls on October 23.
The secular Congress for the Republic placed second with 30 seats and the Democratic Forum for Labor and Liberties, or Ettakatol, came in third with 21 seats.
Some secularists say the Islamists want to concentrate all the power in the hands of the prime minister from Ennahda party, which will lead the new coalition government.
The vote, which came nine months after protesters ousted longtime president Zine el Abidine Ben Ali, was widely considered free and fair and sparked similar uprisings across the Arab world.
The assembly held its historic opening session last month.